Post by: astarmathsandphysics on October 06, 2008, 11:05:57 am
Post by: jinxnumba1 on October 16, 2008, 05:39:53 pm
Post by: astarmathsandphysics on October 16, 2008, 11:09:03 pm
Post by: jinxnumba1 on October 17, 2008, 10:06:11 am
if u do thanks... :)
Post by: fatmajalal on October 24, 2008, 06:40:30 pm
Post by: astarmathsandphysics on October 24, 2008, 07:39:04 pm
Try this link. It has videos too.
Post by: xara on October 26, 2008, 07:46:37 am
http://www.physclips.unsw.edu.au/jw/electricmotors.html
Try this link. It has videos too.
I have prepared for my physics on my own from Stephen Pople's 'Complete Physics for IGCSE', m writing my Paper 6 (alternative to practical) on the following 30th. Do i need to know any more practicals than there are in the book? =O
Post by: astarmathsandphysics on October 26, 2008, 08:01:00 am
Post by: astarmathsandphysics on October 26, 2008, 08:03:39 am
Post by: sonali on November 01, 2008, 12:30:23 pm
ammm i m not at all good at probability
can someone solve d sum fr me
Q . a goalkeeper expects to save one penalty out of every three . calculate d probability tht he :
a) saves one penalty out of d next three
b. fails to save ne of d next three penalties
c. saves two out of d next three penalties
plzzzz give detailed expl fr hw to get this ans
n ya needed notes on or i shld say say some good examples based on d topic THE ANGLE BETWEEN D LINE N D PLANE
PLZZZZ ITS URGENT
N
THX :D
Post by: astarmathsandphysics on November 01, 2008, 08:51:10 pm
or miss, save, misss
or miss, miss, save
The probability of each is 1/3x2/3x2/3=6/27
Therefore total=3x6/27=18/27=2/3
b)If he fails to save one, then he misses them all ie 2/3x2/3x2/3=8/27
c) he can save, save, miss
or save, miss, save
or miss, save, save
the probability of each is 2/3x1/3x1/3=2/27
therefore total is 3x2/27=6/27=2/9
As for the line and plane thing, if you post questions here I will anser them, If you really want me to summarize the topic tell me first, is this a level or igcse. I think you might be in the wrong board.
Post by: sonali on November 02, 2008, 08:45:03 am
a)He can save, miss, mishello astarmathsandphysics
or miss, save, misss
or miss, miss, save
The probability of each is 1/3x2/3x2/3=6/27
Therefore total=3x6/27=18/27=2/3
b)If he fails to save one, then he misses them all ie 2/3x2/3x2/3=8/27
c) he can save, save, miss
or save, miss, save
or miss, save, save
the probability of each is 2/3x1/3x1/3=2/27
therefore total is 3x2/27=6/27=2/9
As for the line and plane thing, if you post questions here I will anser them, If you really want me to summarize the topic tell me first, is this a level or igcse. I think you might be in the wrong board.
thx fr solving d sum
bt ya i still continue to have issues wth this sum as d ans of 1a and 1b does not tally
according to which book i hv taken this frm it says d ans to 1a is 12/27 n to 1b is 26/27
d last ans is correct
n ya as fr d topic d line and between d plane i wldnt mind if u can summarize it
n ya it is fr d igcse level wht i want
thx :D
Post by: astarmathsandphysics on November 02, 2008, 09:51:35 am
Post by: astarmathsandphysics on November 02, 2008, 10:03:53 am
Post by: astarmathsandphysics on November 02, 2008, 10:08:10 am
Post by: sonali on November 02, 2008, 01:07:13 pm
i still dnt get it
Post by: astarmathsandphysics on November 02, 2008, 01:35:32 pm
1/3x1/3x1/3 is the probability that the goalie saves all the shots, so the question must be, "what is the pronanility that the goali does not save all the shots?"
Post by: sonali on November 02, 2008, 01:43:25 pm
1 - 1/3x1/3x1/3.yeah got it thxfully
1/3x1/3x1/3 is the probability that the goalie saves all the shots, so the question must be, "what is the pronanility that the goali does not save all the shots?"
another sum need yr help
srry bt plz do help
its easy bt still i am unable to figure it out
q. a normal pack of 52 cards is shuffled and three cards picked at random. calculate d probability tht all three cards are picture cards.
n ya require notes on d topic the angle between d line n a plane
Post by: astarmathsandphysics on November 02, 2008, 04:03:55 pm
Prob of 1srt being picture card =12/52
prob of 2nd being picture card =11/51
prob of third being picture card =10/50
answer =12/52x11/51x10/50=1320/132600=11/1105
Assuming no replacement.
if they are repaced each time it is 12/52x12/52x12/52=27/2197
will try and put up some of the notes youwant tonight.
Post by: sonali on November 02, 2008, 05:21:36 pm
d ans according to d book is 0.010(3dp)
Post by: astarmathsandphysics on November 02, 2008, 05:47:00 pm
Post by: shivluvchem on November 02, 2008, 09:37:47 pm
A)f-1(1)*inverse*=??
Astarmathphy plz help!!
Im stuck!
Post by: astarmathsandphysics on November 02, 2008, 09:41:02 pm
Post by: shivluvchem on November 02, 2008, 09:44:23 pm
We dunt have log in our sylabus!
The ans is 0!But hoW?
Post by: astarmathsandphysics on November 02, 2008, 09:47:10 pm
Post by: astarmathsandphysics on November 02, 2008, 09:49:40 pm
Post by: shivluvchem on November 02, 2008, 09:51:16 pm
So wats the solution?
Post by: astarmathsandphysics on November 02, 2008, 09:52:59 pm
and inverse is inverse
Post by: shivluvchem on November 02, 2008, 09:55:47 pm
Just let me noe as to how i can obtain an ans as 0!
THe question is on top!
Q. f(x)= 10^x
Q. F(inverse of 1)=?
Post by: astarmathsandphysics on November 02, 2008, 09:58:59 pm
10^0=1
and log101=0
Post by: shivluvchem on November 02, 2008, 10:05:08 pm
And the ans is not 1 it is 0!
It says in the marking scheme!
Post by: astarmathsandphysics on November 02, 2008, 10:10:37 pm
and f-1(x)=10^x
so if you start with 1, you get log1=0 then 10^0=1, but it is irrelevant. It is just to do with f and f-1. You wnd up with the thing you started with
Post by: shivluvchem on November 02, 2008, 10:14:42 pm
Post by: astarmathsandphysics on November 02, 2008, 10:18:55 pm
but but f(f-1(x))=x
an inverse to f undoes f so you end up with what you started.
Post by: igvictim on November 02, 2008, 11:23:14 pm
I am about to have my science paper 3 IG very soon, and I was wondering which are the most common physics equations that appear in this paper.
thank you
Post by: xygoninator on November 03, 2008, 03:12:34 am
Post by: shivluvchem on November 03, 2008, 03:20:15 am
Its a question frm nov 2005...ppr 2!
Im confused!!Help!!!!
Post by: astarmathsandphysics on November 03, 2008, 06:09:02 am
Post by: igvictim on November 03, 2008, 06:20:38 am
Post by: astarmathsandphysics on November 03, 2008, 06:40:55 am
Post by: sonali on November 03, 2008, 07:53:16 am
plzz crack this fr me
plzz give full details oh hw to get to d ans
q. when each edge of a cube is decreased by 1cm, its volume is decreased by 91cm^3 (i mean 91cm cube). find the lenghth of d side of d original cube.
u hv to form eq n solve this
Post by: astarmathsandphysics on November 03, 2008, 08:12:11 am
new volume=(x-1)^3=x^3-3x^2+3x-1
equation is x^3-(x^3-3x^2+3x-1)=91
ie 3x^2-3x+1=91
3x^2-3x-90=0
x^2-x-30=0
(x-6)(x+5)=0
x=6 or -5
but it must be 6 since x must be positive.
Post by: badboy on November 03, 2008, 10:23:39 am
Post by: astarmathsandphysics on November 03, 2008, 10:30:22 am
Post by: badboy on November 03, 2008, 11:29:28 am
Post by: astarmathsandphysics on November 03, 2008, 11:54:02 am
Post by: badboy on November 03, 2008, 01:20:23 pm
Post by: puppy on November 03, 2008, 05:53:31 pm
Post by: pixis on November 03, 2008, 07:41:16 pm
Post by: astarmathsandphysics on November 03, 2008, 10:02:52 pm
can sumone send me the marking schemes for maths paper 2 may/june 05 and 06?? please!!
here they are on www.freeexampapers.com
http://www.freeexampapers.com/Dndex.php?d=SUdDU0UvTWF0aHMvQ0lF&catagory=
Post by: ---<--- StUdYiNg --->--- on November 04, 2008, 04:48:17 pm
Post by: TravisMcDee on November 04, 2008, 05:11:13 pm
need help in math paper 2.hav it tmrw n m stuck in one qns.its frm may june 2008.number 10.can anyone help?? pls.....(Volume factor)=(scale fator)^3
therefore = sqrt(216)=vol factor
=6
Post by: astarmathsandphysics on November 04, 2008, 05:14:07 pm
Therefore length factor = cube root of volume factor
Cube root of 216 is 6
therefore radius =3x6=18
height= 7x6=42
Post by: qwerty on November 04, 2008, 09:52:13 pm
lol ,thanks!
Post by: astarmathsandphysics on November 04, 2008, 10:00:38 pm
Post by: IGCSE Master on November 04, 2008, 10:14:49 pm
f:x = 2x - 1 and g:x = x²-1
Find:
f-¹(x)
gf(x)
Post by: astarmathsandphysics on November 04, 2008, 10:21:01 pm
Make x the subject
f+1 =2x so (f+1)/2=x
Now swap f and x
(x+1)/2=f
Now replace f by f^-1 to give (x+1)/2=f^-1
g(x)=x^2-1 so g(f)=f^2-1 but f(x)=2x-1
so g(f(x))=(2x-1)^2-1
=(2x-1)(2x-1)-1
=4x^2-2x-2x+1-1
=4x^2-4x
Post by: qwerty on November 04, 2008, 10:27:22 pm
f(x) = 3 x - 1
f^-1(x) would then be:
f = 3x-1
f + 1 = 3x
f+1/3 = x
swap
x+1/3 = f
f^-1 = x+1/3
is that correct??
thanks a lot!!!
Post by: astarmathsandphysics on November 04, 2008, 10:29:10 pm
x+1 has to be divided by 3 not just 1 divided by 3
Post by: qwerty on November 04, 2008, 10:34:20 pm
Post by: blah4444 on November 04, 2008, 10:46:43 pm
thanks
Post by: astarmathsandphysics on November 04, 2008, 11:01:18 pm
21^2=x^2+92x)^2-x*2x*cos120
441=x^2+4x^2-4x^2*-1/2
441=5x^2+4x^2
441=9x^2
so x=sqrt(441/9)=7
Post by: igvictim on November 05, 2008, 01:13:05 am
cheers
Post by: qwerty on November 05, 2008, 02:08:29 am
how do i know what method to use?
for example:
6ab - 9bx - 21by
i would easily transform into:
3b (2a - 3x - 7y)
but, for example:
k² + 9k + 8
what should be done?thanks!
Post by: astarmathsandphysics on November 05, 2008, 07:20:10 am
The answer is 1 and 8 so it factorises as (x+1)(x+8)
Post by: unknown on November 18, 2008, 12:10:57 pm
want d whole chap summarisd if possible
n ya need help in reflection where the mirror line is slanting
Post by: astarmathsandphysics on November 18, 2008, 12:24:32 pm
It is summarized here.
Post by: unknown on November 18, 2008, 12:34:37 pm
bt ya need fr sheer too
Post by: unknown on November 20, 2008, 12:20:03 pm
a(-2,2) b(2,2) c(2,-2) d(-2,-2)
a'(-2,6) b'(6,2) c'(2,-6) d'(-6,-2)
a"(-6,8) b"(-2,-4) c"(6,-8) d"(2,4)
a) find the matrix which maps abcd onto a'b'c'd'
b) find the matrix which maps a'b'c'd' onto a"b"c"d"
c) find the matrix which maps abcd onto a"b"c"d"
d) find the matrix which maps a"b"c"d" onto abcd (this shalll be d inverse of d ans c rite)
plzz give a detailed explanation of hw to get to d ans
the need is urgent
thx fr d help :D
Post by: astarmathsandphysics on November 21, 2008, 11:20:50 am
the coordinates of the vertices of a square abcd after two transformation are as folllows
a(-2,2) b(2,2) c(2,-2) d(-2,-2)
a'(-2,6) b'(6,2) c'(2,-6) d'(-6,-2)
a"(-6,8) b"(-2,-4) c"(6,-8) d"(2,4)
a) find the matrix which maps abcd onto a'b'c'd'
b) find the matrix which maps a'b'c'd' onto a"b"c"d"
c) find the matrix which maps abcd onto a"b"c"d"
d) find the matrix which maps a"b"c"d" onto abcd (this shalll be d inverse of d ans c rite)
plzz give a detailed explanation of hw to get to d ans
the need is urgent
thx fr d help :D
| 2 2 |
Post by: unknown on November 21, 2008, 11:43:58 am
wht is 2 2
Post by: astarmathsandphysics on November 21, 2008, 11:52:01 am
Post by: astarmathsandphysics on November 21, 2008, 11:58:58 am
(c d)(2) = (6)
multiply out to get -2a+2b=-2 and -2c+2d=2
Similarly with b to b' etc. Solove the simulateous equations in a and b c d to get the matrix (2 1)
(1 2)
b)Follow the procedure from a to get (0 -1)
(-1 1)
c)(0 -1)(2 1)
(-1 1)(1 2 )
Multiply the matrices to get(-1 -2)
(-1 1)
d) (1/3 -2/3)
(1/3 -1/3)
It is dificult to give a detailed explanation with something like latex. We will have to get some notaion software.
Post by: unknown on November 22, 2008, 02:23:30 pm
Post by: astarmathsandphysics on November 22, 2008, 03:02:53 pm
Post by: Alk on December 21, 2008, 03:37:16 pm
Post by: astarmathsandphysics on December 21, 2008, 04:05:02 pm
Post by: Alk on January 09, 2009, 12:37:16 pm
thank you very much.
Post by: astarmathsandphysics on January 09, 2009, 01:04:37 pm
Post by: astarmathsandphysics on January 09, 2009, 01:09:52 pm
Post by: Alk on March 01, 2009, 12:49:59 pm
can you explain to me , how to solve Q 2 (c) P3 October/November 2005?
thank you very much
Post by: astarmathsandphysics on April 10, 2009, 07:19:07 pm
4 15 44 103 204
1st diff 11 29 59 101
2nd diff 18 30 42
3rd diff 12 12 so 12/6=2 It is a
Do a
Take this away from the original sequence
2 -1 -10 -25 -46
This is a quadratic sequence
1st diff -3 -9 -15 -21
2nd diff -6 -6 -6 -6 -6/2=-3
Do a
Take this away from the quadratic sequence 5 11 17 23. This is linear, the difference is 6 so it is a 6n-1 sequence and the complete rule is
Post by: SGVaibhav on April 10, 2009, 07:41:25 pm
Post by: sweetsh on April 10, 2009, 08:37:10 pm
The file is not opening ???
Im wondering.....?
Post by: astarmathsandphysics on April 11, 2009, 01:10:54 am
Post by: moraesikae on April 11, 2009, 04:32:07 am
Which file doesn't open?
The fileu have attached doesnt open. :( :(
Post by: astarmathsandphysics on April 11, 2009, 08:17:32 am
Post by: astarmathsandphysics on April 11, 2009, 05:15:45 pm
hey astartphysicsandmaths,I managed to find it
it would be graet if you could send the attachment at the following address fireoffuzail007@hotmail.com
thank you. :)
Post by: esum0209 on April 11, 2009, 05:25:08 pm
do u have notes on digital electonics in physics?(like all the logic gates and stuff). I also need notes on how to do find the formula on linear and quadratic sequence in maths.
Thanks
Post by: astarmathsandphysics on April 11, 2009, 06:07:37 pm
Post by: astarmathsandphysics on April 11, 2009, 06:14:29 pm
http://www.allaboutcircuits.com/worksheets/trouble_gates.html
Post by: sweetsh on April 11, 2009, 06:17:18 pm
Thank you!!
Post by: astarmathsandphysics on April 11, 2009, 06:24:48 pm
Post by: geekindahouse on April 12, 2009, 09:57:25 am
Post by: esum0209 on April 12, 2009, 01:02:49 pm
Thanks for the other notes
Post by: astarmathsandphysics on April 12, 2009, 01:13:06 pm
3 9 17 27 39 is a quadratic sequence
1st diff 6 8 10 12
2nd diff 2 2 2 2
therefore 2/2=1n^2 sequence
Do an n^2 line 1 4 9 16 25 and take away from original sequence
2 5 8 12 This is a linear sequence with diff 3 therefore it is a 3n sequence. To get the first number in this linear sequence with have to take 1 from this 3 so ans=1n^2+3n-1
4 10 16 22 28 is a linear sequence with 1st diff 6 therefore it is a 6n sequence. take 2 from 6 to get 4 so rule is 6n-4
Post by: sweetsh on April 12, 2009, 01:47:19 pm
Post by: SGVaibhav on April 12, 2009, 02:04:10 pm
Post by: emi on April 12, 2009, 02:33:46 pm
Post by: astarmathsandphysics on April 12, 2009, 02:46:26 pm
Divide a 3rd difference line by3x2x1=6
divide a 2nd difference line by2x1=2
Divide a 1st difference line by1
Post by: sweetsh on April 12, 2009, 02:49:06 pm
Post by: emi on April 12, 2009, 03:27:17 pm
this is an Question in the trigonometry can you tell me how to solve it ?? at MS the answer is 52.4 .
thanks
Post by: sweetsh on April 12, 2009, 03:29:11 pm
Post by: emi on April 12, 2009, 03:46:47 pm
Post by: astarmathsandphysics on April 12, 2009, 06:06:04 pm
an observer at the top of a tower of height 20m sees a man due east if him at an angle of depression of 27 degree . He sees another man due south oh him at an angel of depression of 30 degree. find the distance between the two men on the ground .Horizontal distance from tower to 1st man: tan27=o/a=20/a so a=20/tan27=39.25
this is an Question in the trigonometry can you tell me how to solve it ?? at MS the answer is 52.4 .
thanks
Horixontal distance from tower to 2nd man=20/tan30=34.64
There is a right angle between these 2 lengths so use Pythagoras theorem
d=sqrt(39.25^2+34.64^2)=52.4m
Post by: emi on April 12, 2009, 06:28:40 pm
=(
Post by: astarmathsandphysics on April 12, 2009, 06:32:42 pm
Post by: emi on April 12, 2009, 06:44:41 pm
i got it now =D
Post by: emi on April 18, 2009, 08:15:06 pm
Q: The sum of two numbers is 131. Twice of one number is 5 less than the other . find the numbers
at the back of the book answers are " 42 and 89 "
Post by: sweetsh on April 18, 2009, 08:41:04 pm
By simultaneous equations.
Let the numbers are x,y
x+y=131
this is equation (1)
now.. 2x-y=5
as 2x+5=y
now solve it.
you will get x=42 and y=89
Post by: astarmathsandphysics on April 18, 2009, 08:52:39 pm
Post by: emi on April 18, 2009, 08:58:28 pm
Post by: sweetsh on April 18, 2009, 09:05:53 pm
Post by: hyebyekadal on April 21, 2009, 02:29:24 pm
1.One of the laws about the behaviour of gases states that
“For a fixed amount of gas at constant temperature, the pressure is inversely proportional
to the volume”.
In the space below, write an equation that represents this law.
So i wrote P=1/V
but the ms says that NOT correct and the correct ans is pV=constant
2.Explain, in terms of molecules, how thermal expansion takes place in a solid and in a
gas.
P.S. I got the gas part, need hwlp on the solid part.
Sold:
My ans:The molecules gain more kinetic energy and and vibrate more annd faster. Thus the molecules require greater space.
MS:SOLID higher temperature means higher energy/greater speed of
mols/particles/atoms
NOT more vibration NOT vibrate more
Post by: astarmathsandphysics on April 21, 2009, 04:01:25 pm
OK guys I did some phy papers and I had some doubts (this is paper 3 2008 June , 2nd vairent)
1.One of the laws about the behaviour of gases states that
“For a fixed amount of gas at constant temperature, the pressure is inversely proportional
to the volume”.
In the space below, write an equation that represents this law.
So i wrote P=1/V
but the ms says that NOT correct and the correct ans is pV=constant
2.Explain, in terms of molecules, how thermal expansion takes place in a solid and in a
gas.
P.S. I got the gas part, need hwlp on the solid part.
Sold:
My ans:The molecules gain more kinetic energy and and vibrate more annd faster. Thus the molecules require greater space.
MS:SOLID higher temperature means higher energy/greater speed of
mols/particles/atoms
NOT more vibration NOT vibrate more
should be P=k/v which is equivalent to PV=k
2. When a solid is heated the molecules vibrate against each other and push each other apart.
Post by: SGVaibhav on April 21, 2009, 04:59:36 pm
Post by: astarmathsandphysics on April 21, 2009, 05:13:24 pm
Post by: hyebyekadal on April 21, 2009, 05:54:06 pm
thanx again for answering anyway!
Post by: astarmathsandphysics on April 21, 2009, 08:24:47 pm
Post by: nid404 on April 22, 2009, 07:17:40 am
Q.The air in a bicycle tyre has a volume of 1000cm3 and a pressure of 2.5 atmospheres. If the air is released ( at the same temperature) so its pressure is 1 atmosphere, what is the volume of the air?
This part needs help
A bicycle has a volume of 100cm3 and is now used to pump up the tyre. After 1 stroke of the pump, what is the presure in the tyre?
Thanks
Post by: astarmathsandphysics on April 22, 2009, 08:35:25 am
The second part of the question needs help.
Q.The air in a bicycle tyre has a volume of 1000cm3 and a pressure of 2.5 atmospheres. If the air is released ( at the same temperature) so its pressure is 1 atmosphere, what is the volume of the air?
This part needs help
A bicycle has a volume of 100cm3 and is now used to pump up the tyre. After 1 stroke of the pump, what is the presure in the tyre?
Thanks
pV=constant so 2.5x1000=2500=pV=1xV so V=2500cm^3
The air had volume of 2500 at 1atmosphere but we put in an extra 100 so new volume at 1 atmosphere is 2600cm^3
pV=1X2600=px1000 so p=2.6 atmospheres.
Post by: hyebyekadal on April 22, 2009, 08:56:44 am
Post by: nid404 on April 22, 2009, 09:56:51 am
Quote
pV=constant so 2.5x1000=2500=pV=1xV so V=2500cm^3
The air had volume of 2500 at 1atmosphere but we put in an extra 100 so new volume at 1 atmosphere is 2600cm^3
pV=1X2600=px1000 so p=2.6 atmospheres.
I tried the same thing earlier but the answer to this question is 1.1 atmospheres. How do you derive that?
And this question was found in a physics textbook for IGCSE known as Physics For You by Keith Johnson. I don't know whether it was taken from any past paper.
anyways thanks for your help.
Post by: SGVaibhav on April 22, 2009, 10:23:08 am
Post by: astarmathsandphysics on April 22, 2009, 11:06:58 am
QuotepV=constant so 2.5x1000=2500=pV=1xV so V=2500cm^3
The air had volume of 2500 at 1atmosphere but we put in an extra 100 so new volume at 1 atmosphere is 2600cm^3
pV=1X2600=px1000 so p=2.6 atmospheres.
I tried the same thing earlier but the answer to this question is 1.1 atmospheres. How do you derive that?
And this question was found in a physics textbook for IGCSE known as Physics For You by Keith Johnson. I don't know whether it was taken from any past paper.
anyways thanks for your help.
How can youn pump in 100cm^3 more air and have the pressure fall from 2.5 to 1 atmosphere?
Post by: SGVaibhav on April 24, 2009, 10:17:51 am
If possible, can u show it with a diagram?
Post by: astarmathsandphysics on April 24, 2009, 10:25:03 am
Post by: SGVaibhav on April 24, 2009, 10:37:37 am
there r many answers.
in markscheme they just write, correct method shown
i cannot ask my teacher also, because i have holidays.
so can u show me few ways
Post by: astarmathsandphysics on April 24, 2009, 10:49:09 am
Post by: SGVaibhav on April 24, 2009, 11:27:21 am
he thing is that it is Alternative to Practical Paper, not a practical paper.
so we have to write methods to measure. if the thing would be in front of me, i would have measured in some crappy way. but over here, we cant do that
Post by: astarmathsandphysics on April 24, 2009, 11:29:27 am
Post by: SGVaibhav on April 24, 2009, 12:18:26 pm
i think i am not able to express my question clearly.
i will show u the link to the exact question, that will help
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvUGh5c2ljcy9DSUUvMjAwMiBOb3YvMDYyNV93MDJfcXBfNi5wZGY=
Q5)b) (can u show me atleast 2 methods please)
Thanx
:D
Post by: nid404 on April 24, 2009, 12:24:17 pm
QuotepV=constant so 2.5x1000=2500=pV=1xV so V=2500cm^3
The air had volume of 2500 at 1atmosphere but we put in an extra 100 so new volume at 1 atmosphere is 2600cm^3
pV=1X2600=px1000 so p=2.6 atmospheres.
I tried the same thing earlier but the answer to this question is 1.1 atmospheres. How do you derive that?
And this question was found in a physics textbook for IGCSE known as Physics For You by Keith Johnson. I don't know whether it was taken from any past paper.
anyways thanks for your help.
How can youn pump in 100cm^3 more air and have the pressure fall from 2.5 to 1 atmosphere?
I'll answer the question I posted. I know that's absurd but it's just to make sure others reading it do not get it wrong.
Q. a)The air in a bicycle tyre has a volume of 1000cm3 and a pressure of 2.5 atmospheres. If the air is released ( at the same temperature) so its pressure is 1 atmosphere, what is the volume of the air?
b)A bicycle has a volume of 100cm3 and is now used to pump up the tyre. After 1 stroke of the pump, what is the presure in the tyre?
Ans:
(a) V1= 1000 cm3, P1= 2.5 atm. V2= ?, P2= 1 atm.
Using Boyle’s Law,
P1V1 = P2V2
V2 = P1V1/P2
= 2500 cm3
(b) According to Boyle’s law,
Pressure and volume is inversely proportional to each other,
Hence if volume decreases, the pressure increases but in same ratio,
Since the volume of the pump is 100 cm3, and volume of the tyre is 1000cm3, the ratio of the decrease in volume after one stroke = 100/1000=0.1
Hence the ratio by which the pressure will increase is 0.1 atm.
Hence total pressure in the tyre = 1 atm + 0.1 atm
= 1.1 atm
Post by: astarmathsandphysics on April 24, 2009, 01:13:52 pm
Hence total pressure in the tyre = 1 atm + 0.1 atm
= 1.1 atm
THE AIR IN THE TYRE IS NEVER AT A PRESSURE OF 1 ATM. IT IS 2.5 ATM
Sorry to write in capitals but I had to make you read this.
Post by: astarmathsandphysics on April 24, 2009, 01:22:48 pm
Post by: sweetsh on April 24, 2009, 01:25:37 pm
Post by: sweetsh on April 24, 2009, 01:30:34 pm
log2x-log4(x-4)=2
?
Post by: kenyas sweetheart on April 24, 2009, 01:40:54 pm
may, june 03,
question 2b.
how do we find the speed? do we add? or minus? help pls, =)
and the same paper 7c.
whats the apparatus we need?
please help me!
Post by: astarmathsandphysics on April 24, 2009, 01:41:06 pm
we have log4x2-log4(x-4)=2
log4(x2/(x-4))=2
(x2/(x-4)=42 so x2=16(x-4)=16x-64
so x2-16x+64=0
(x-8)2=0 so x=8
Post by: astarmathsandphysics on April 24, 2009, 01:43:13 pm
hi, i need help in this question please:
may, june 03,
question 2b.
how do we find the speed? do we add? or minus? help pls, =)
and the same paper 7c.
whats the apparatus we need?
please help me!
What course code is this question from?
Post by: sweetsh on April 24, 2009, 01:44:00 pm
Post by: SGVaibhav on April 24, 2009, 02:35:39 pm
It is only a 1 mark question. Why do you have nightmares? Use a meter rule either on the bench or in a clamp.
i dont know why i am scared :'( :'(
i get scared when nothing goes in my mind.
what is a clamp?
Post by: SGVaibhav on April 24, 2009, 02:36:51 pm
Post by: astarmathsandphysics on April 24, 2009, 02:40:51 pm
Clamp metal rod with hand attached, worked by a screw so you can open and close the fingers.It is only a 1 mark question. Why do you have nightmares? Use a meter rule either on the bench or in a clamp.
i dont know why i am scared :'( :'(
i get scared when nothing goes in my mind.
what is a clamp?
Post by: sweetsh on April 24, 2009, 02:42:49 pm
Post by: astarmathsandphysics on April 24, 2009, 02:45:08 pm
Post by: SGVaibhav on April 24, 2009, 02:47:00 pm
u mean both? (IGCSE and ADDITional Maths?)
is that a clamp? when i went to search for clamps in google, i got weird dolls and all that. so i wanted to ask, is this a clamp?
Post by: sweetsh on April 24, 2009, 02:50:27 pm
By the way Im forced for the additional maths by my school
Post by: astarmathsandphysics on April 24, 2009, 02:51:45 pm
??? ???
u mean both? (IGCSE and ADDITional Maths?)
is that a clamp? when i went to search for clamps in google, i got weird dolls and all that. so i wanted to ask, is this a clamp?
This is a laboratory clamp
Post by: SGVaibhav on April 24, 2009, 03:01:23 pm
how can that be aligned to calculate the dist between lens and screen.
THIS IS PISSING ME OFF WHILE I DONT WANT TO GET PISSED OFF.
HRMPH WHY AM I GETTING PISSED OFF?
lol haahahah typing made me laugh. yeeeeh im not pissed off anymore
:D ;D ;D ;D ;D ;D :D :D :D 8) 8) 8) 8)
sigh chill pill
Post by: sweetsh on April 24, 2009, 03:12:20 pm
Post by: SGVaibhav on April 24, 2009, 04:01:39 pm
i found a kool thing on my scale.
i will scan or post a picture after some time.
it got mutated
the whole properties of the glass (plastic) has chnaged.
it looks so weirdoo
Post by: SGVaibhav on April 24, 2009, 04:15:17 pm
(Q)uestion---->1)b)i)
How do i do this?
This is written in the markscheme, but nothing went in my mind!
correct diagram, blocks parallel, one at each end
can anyone draw rough rectangles in paint, and show it to me?
Post by: astarmathsandphysics on April 24, 2009, 04:39:50 pm
Post by: sweetsh on April 24, 2009, 05:13:10 pm
Post by: emi on April 24, 2009, 05:44:45 pm
can u give me some tips to know how to do them ?
i mean there is no specific things in the book for paper 6, we have to know everything .
i have troubels in physics and biology
Post by: SGVaibhav on April 24, 2009, 05:51:39 pm
problems r encountered when an attempt is made to solve it.
i have this next
STUPID IDIOT DUMB FOOLISH .... PROBLEM
how to write a scale in a graph.
everyone is experienced (lol)
but look at this markscheme.
they have a unique way of writing.
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvUGh5c2ljcy9DSUUvMjAwNCBOb3YvMDYyNV93MDRfbXNfNi5wZGY=
maybe this is a igcse unique way.
Q 3c
sweetsh, can u try to help me in writing scales for graph after reading that mark scheme.
Thanks
;D
Post by: sweetsh on April 24, 2009, 05:52:57 pm
Post by: SGVaibhav on April 24, 2009, 05:54:15 pm
By the way my question is (somehow) too freaky (not freaky, i dont get the proper adjective)
Post by: sweetsh on April 24, 2009, 06:05:28 pm
Post by: SGVaibhav on April 24, 2009, 06:09:16 pm
i just saw replies being posted while i was typing.
and they were asked to u.
so i wrote that.
plz answer my question. it will take u 30 seconds. (or less maybe)
Post by: sweetsh on April 24, 2009, 06:17:38 pm
Post by: SGVaibhav on April 24, 2009, 06:19:54 pm
not that easy.
problems r encountered when an attempt is made to solve it.
i have this next
STUPID IDIOT DUMB FOOLISH .... PROBLEM
how to write a scale in a graph.
everyone is experienced (lol)
but look at this markscheme.
they have a unique way of writing.
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvUGh5c2ljcy9DSUUvMjAwNCBOb3YvMDYyNV93MDRfbXNfNi5wZGY=
maybe this is a igcse unique way.
Q 3c
sweetsh, can u try to help me in writing scales for graph after reading that mark scheme.
Thanks
;D
this one
Post by: sweetsh on April 24, 2009, 08:50:39 pm
Sometimes they tell you but usually the quantity that you calculate is on the y axis and the quantity that is there already on x axis.We should check from astar
Post by: astarmathsandphysics on April 24, 2009, 09:34:18 pm
Oh you mean when you want to draw a graph? What to put on x and y axises?
Sometimes they tell you but usually the quantity that you calculate is on the y axis and the quantity that is there already on x axis.We should check from astar
That is true, and there are also dependent and independent quanities. The indepdenent one is the one that cant be controlled, like time, and goes on the x axis.
Post by: sweetsh on April 24, 2009, 09:36:51 pm
Thanks astar for making us sure
Post by: SGVaibhav on April 25, 2009, 08:11:49 am
i got it answered by sum1 else (and my question was pretty dumb)
:D
Post by: SGVaibhav on April 25, 2009, 12:48:07 pm
serious topic
not a small question
its about reflection in plane mirror.
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvUGh5c2ljcy9DSUUvMjAwNSBOb3YvMDYyNV93MDVfcXBfNi5wZGY= (O/N 05 Paper6)
Q4)f)
Explain me, and do we draw reflected ray? (markscheme not helping :( )
Post by: cockyxrocker on April 25, 2009, 01:47:43 pm
Post by: SGVaibhav on April 25, 2009, 02:05:24 pm
Post by: twilight on April 25, 2009, 02:06:27 pm
Post by: SGVaibhav on April 25, 2009, 06:02:59 pm
need help
serious topic
not a small question
its about reflection in plane mirror.
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvUGh5c2ljcy9DSUUvMjAwNSBOb3YvMDYyNV93MDVfcXBfNi5wZGY= (O/N 05 Paper6)
Q4)f)
Explain me, and do we draw reflected ray? (markscheme not helping :( )
Mr. Paul, plz help me in this question.
ok this is for 4 marks, not small ones like b4, my question is there in the quote
Thank You
:D
Post by: astarmathsandphysics on April 25, 2009, 06:18:42 pm
Post by: SGVaibhav on April 25, 2009, 06:26:25 pm
Or you could use the angle v, tanv=x/y. ( i did not get this)
and do we draw reflected ray?
i understood till question E
but i cant do part F only.
regarding drawing softwares, currently i am searching a software that can measure pdf files, so i can do these questions without printing itself.
Post by: astarmathsandphysics on April 25, 2009, 06:45:14 pm
Post by: SGVaibhav on April 25, 2009, 06:51:35 pm
it is not clear in markscheme
Post by: astarmathsandphysics on April 25, 2009, 07:18:26 pm
Post by: SGVaibhav on April 25, 2009, 08:19:19 pm
:D
Post by: zubair_slipknot on April 26, 2009, 12:17:12 pm
i was having a problem in the may june paper 4 2008 question no.1 (the ratio one of Cairo and Addis Ababa)
can someone help me out in this even though i am good at maths i dunnno why i am not getting it ryt...
1(a) The scale of a map is 1:20 000 000
On the map, the distance between cairo and Addis Ababa is 12cm.
(i) Calculate the distance,in Km, between Cairo and Addis Ababa.
(ii) On the map the area of a desert regionis 13 square centimetres
Calculate the actual area of this desert region, in square Km
(b) (i) The actual distance between Cairo and Khartoum is 1580Km.
On a diffrent map this distance is represented by 31.6cm.
Calculate, in the form 1:n, the scale of this map.
thx for help and support if anyone can do this as soon as possible...
Post by: sweetsh on April 26, 2009, 12:34:02 pm
Post by: sweetsh on April 26, 2009, 07:52:14 pm
Post by: astarmathsandphysics on April 26, 2009, 08:49:04 pm
Post by: cockyxrocker on April 27, 2009, 06:02:16 am
Quote
my friend has some notes 4 these topics .. i'll try to get them for u asap.. dont worrythanks for helpin '
though i need them asap
Post by: twilight on April 27, 2009, 09:44:08 am
but i swear i am trying
Post by: sweetsh on April 27, 2009, 07:40:21 pm
Post by: SGVaibhav on April 28, 2009, 07:11:50 pm
this paper
may june 05 paper 4 igcse
http://www.freeexampapers.com/FreeExamPapers.com_.php?__lo=SUdDU0UvTWF0aHMvQ0lFLzIwMDUgSnVuLzA1ODBfczA1X3FwXzQucGRm
Questions
7)a)i (plz try it out) answer is 46.5
8)a) (2 answers====>1 and 3 {HOW?})
plz
Post by: sweetsh on April 28, 2009, 07:25:08 pm
you go to 75 on the cumulative column and you draw a line to see how much is the speed.
8)a) f(x) = x2 – 4x + 3
y=x2 -4x + 3
y= (x-3) (x-1)
x=3 or x=1
Post by: SGVaibhav on April 28, 2009, 07:32:05 pm
i got same thing for 7a)
but when i did that thing on graph, my answer is completely different.
try it out in ur pc only without printing
that is :@
it is (46.5 in markscheme) how the f***?
in 8a
i understood
but i had one quesiton
when do the thing we did below and when do we actually substitute?
i am little confused with that.
Post by: sweetsh on April 28, 2009, 07:45:01 pm
Post by: astarmathsandphysics on April 28, 2009, 07:52:32 pm
Post by: sweetsh on April 28, 2009, 07:56:59 pm
Post by: SGVaibhav on April 28, 2009, 08:11:43 pm
i think mine is faulty
lol
can u explain me the 8th one
{MINE QUOTE}
in 8a
i understood
but i had one quesiton
when do the thing we did below and when do we actually substitute?
i am little confused with that.
ok the answer is coming right now!
thanx for that one
Post by: sweetsh on April 28, 2009, 08:12:54 pm
Post by: SGVaibhav on April 28, 2009, 08:19:05 pm
ok 7) a) 50/100 *150 =75
you go to 75 on the cumulative column and you draw a line to see how much is the speed.
8)a) f(x) = x2 – 4x + 3
y=x2 -4x + 3
y= (x-3) (x-1)
x=3 or x=1
ugh
i cant explain it
i understood.
i cant express my question, but i know the right thing now
it is very hard to explain over here.
i rubbed the whole thing 5 times and wrote it again.
THANK YOU FOR HELP
:D
Post by: SGVaibhav on April 30, 2009, 04:50:44 pm
in maths
while doing a question, how much DP or SF do we use?
and we write our answers to how much SF or DP?
because this has been ruining my accuracy.
Post by: twilight on April 30, 2009, 04:59:13 pm
for the final answer u have to put ur answer to 3 SF but to 1 DP for degrees
so while doing the question put ur answer to 4 SF or 2 DP in case of degrees
hope u get ur answers accurate
Post by: SGVaibhav on April 30, 2009, 08:00:28 pm
+rep
Post by: unknown on May 03, 2009, 12:51:58 pm
Use the graph to find the two values of k.
wht do u mean by this n ya i require help in d specimen paper q of 2009 maths paper part 4f,g
plz its urgent
thx in advance n ya d ans for phy 2
d q is
(b) Describe how the circuit works as the external light intensity decreases and the lamp
comes on.
its frm oct nov 2008
plz with proper explaination
Post by: astarmathsandphysics on May 03, 2009, 01:09:44 pm
Post by: hyebyekadal on May 03, 2009, 05:43:18 pm
im not too sure becuase i did this paper long time ago and dont have it with me now so ya i got kinda confused to but look carfully ull find that theres only 2 points on graph line were theres 2 points which have same y value but diff x values .. others have 3 or 1....im in a hurry so..
Post by: unknown on May 04, 2009, 05:03:03 am
Post by: astarmathsandphysics on May 04, 2009, 06:40:10 am
Post by: hyebyekadal on May 04, 2009, 08:19:17 am
Post by: astarmathsandphysics on May 04, 2009, 08:20:24 am
Post by: unknown on May 04, 2009, 09:03:21 am
Post by: astarmathsandphysics on May 04, 2009, 09:11:35 am
Post by: ny on May 04, 2009, 07:12:34 pm
could anyone please explain to me for this question:
-OCT/NOV 2008 mathematics paper 2( both variants) question 5.it has smthng that i don't really undrstand.i know its about locus but how? my teacher didnt teach us this type of question.thank you.
Post by: yinyang on May 04, 2009, 07:24:06 pm
then draw a circle with 90 degrees
the arc drawn is the path taken by point D when it is rotated by 90 degrees about point B
Post by: emi on May 04, 2009, 09:27:03 pm
M/J 2008 Q4.
(a)- i & ii
thanks
Post by: sweetsh on May 04, 2009, 09:28:20 pm
Post by: emi on May 04, 2009, 09:29:37 pm
Post by: sweetsh on May 04, 2009, 09:39:01 pm
and ii) im not sure of it really
Post by: emi on May 04, 2009, 09:43:08 pm
you didn't do it ? because of those steps i cant move forward to solve the rest of that Question
Post by: sweetsh on May 04, 2009, 09:49:58 pm
all lines present, thin, neat and in correct area
normal at 90° (by eye)
and EF at 30° to normal (by eye)
line KJ to at least beyond P4
Post by: astarmathsandphysics on May 04, 2009, 10:05:46 pm
i do have a silly question here.
could anyone please explain to me for this question:
-OCT/NOV 2008 mathematics paper 2( both variants) question 5.it has smthng that i don't really undrstand.i know its about locus but how? my teacher didnt teach us this type of question.thank you.
Locus - the set of points. As the square is rotated D traces out a circle.
Post by: astarmathsandphysics on May 04, 2009, 10:18:03 pm
can any one help me with this physics Question.
M/J 2008 Q4.
(a)- i & ii
thanks
Draw NN' 2cm from A paraLELL TO AD, and the line EF starts 30 to the left coming from the top.
Post by: emi on May 04, 2009, 10:29:37 pm
thanks alot
Post by: emi on May 04, 2009, 10:46:15 pm
they say extend the line EF through Out line of the block to a point J. the line EJ crosses the line CD label this point K
Post by: ny on May 05, 2009, 02:32:15 am
Post by: unknown on May 05, 2009, 04:44:52 am
thx a million in advance n i wldnt mind if others can help me out 2
Post by: astarmathsandphysics on May 05, 2009, 07:41:29 am
sry im stuck in the same Question part c)
they say extend the line EF through Out line of the block to a point J. the line EJ crosses the line CD label this point K
Just carry on the line EF. It doesnt matter where J is as long as it is on the other side of the block.
Post by: ny on May 05, 2009, 12:05:25 pm
Post by: emi on May 05, 2009, 12:45:15 pm
can any one attach the M/J 08 paper 6 ? i cant get to FEP .. so i can show the block
Post by: sweetsh on May 05, 2009, 12:51:56 pm
Post by: emi on May 05, 2009, 12:54:59 pm
this might sound silly but what position should i keep my protractor ?
Post by: X Abdulrahman X on May 06, 2009, 05:28:50 pm
Question 8, (c)
The three 60W lamps are replaced by 3 energy-saving ones, that give the same light output buy are rated at only 15W each.
Calc,
(i) The total reduction in power...
(ii) the energy saved when the lamps are lit for 1hr...
Could someone explain this with the working out pls, only the answers are written in the mark scheme. Thank You
Post by: emi on May 06, 2009, 08:17:42 pm
first calculate both the powers before and after
P1 before replacing: 60x3= 180w
P2 after replacing: 15x3= 45w
subtract ____________
135 w is the reduction in power
ii) energy saved when lights are lit for one hour
calculate the energy while using 3 ,60w lamps = VIT = 60x3x3600 = 64000
calculate the engery while using 3, 15w lamps = VIT = 15x3x3600 =162000
subtract __________
486000 J energy saved 468 KJ
Post by: X Abdulrahman X on May 07, 2009, 04:24:14 am
looks like u will do well in ur physics :P
Post by: emi on May 07, 2009, 06:03:09 am
Post by: emi on May 09, 2009, 02:44:22 am
Q- a 3kW electric heater is used to heat up 2.5kg of water of specific latent heat capacity 4200J/kg/c . the initial temp is 16 degree. Work out the final temp. after the heater has been switched on for 2 minutes ?
wats the way to solve this ??? plz someone
Post by: astarmathsandphysics on May 09, 2009, 03:25:48 am
Post by: zbzbzb25 on May 09, 2009, 08:41:35 am
this site
www.mathsandphysics.com
they hav quite a lot of notes
Post by: X Abdulrahman X on May 09, 2009, 12:14:56 pm
Question 5 b (i+ii)
Might sound like a stupid question but how do we do it ? >.<
Post by: astarmathsandphysics on May 09, 2009, 12:21:20 pm
C from B 360-(10+90+115)=145
Post by: X Abdulrahman X on May 09, 2009, 12:28:32 pm
Post by: june on May 09, 2009, 02:13:39 pm
Nov 07 p2 Q12: A and B are sets write the following sets in thier simplest form
a) A n A'
b)A u A'
c) (A u B) U (A n B')
16a) A car manufacturer sells a similar, sclale model of one of its real cars
a) the fuel tank of the real car has a volume of 64litres and the fuel tank of the model has a volume of 0.125 litres.. show that the length of the real car is 8 times the length of the model car
May june 08 p2 q21..
http://www.freeexampapers.us/IGCSE/Maths/CIE/2008%20Jun/0580_s08_qp_2.pdf
NOT TO
SCALE
N
ABCD, BEFC and AEFD are all rectangles.
ABCD is horizontal, BEFC is vertical and AEFD represents a hillside.
AF is a path on the hillside.
AD = 800 m, DC = 600 m and CF = 200 m.
(a) Calculate the angle that the path AF makes with ABCD.
Answer(a) [5]
(b) In the diagram D is due south of C.
Jasmine walks down the path from F to A in bad weather. She cannot see the path ahead.
The compass bearing she must use is the bearing of A from C.
Calculate this bearing.
Answer(b) [3]
Post by: astarmathsandphysics on May 09, 2009, 02:37:49 pm
Post by: hyebyekadal on May 09, 2009, 07:40:22 pm
P.S. I have attacehd this particular question if you haven't noticed yet!
Post by: Christy on May 09, 2009, 07:42:58 pm
Please i need help with these math questioons, with explanation on how u did it.. thanksssssssssssss
Nov 07 p2 Q12: A and B are sets write the following sets in thier simplest form
a) A n A'
b)A u A'
c) (A u B) U (A n B')
16a) A car manufacturer sells a similar, sclale model of one of its real cars
a) the fuel tank of the real car has a volume of 64litres and the fuel tank of the model has a volume of 0.125 litres.. show that the length of the real car is 8 times the length of the model car
May june 08 p2 q21..
http://www.freeexampapers.us/IGCSE/Maths/CIE/2008%20Jun/0580_s08_qp_2.pdf
NOT TO
SCALE
N
ABCD, BEFC and AEFD are all rectangles.
ABCD is horizontal, BEFC is vertical and AEFD represents a hillside.
AF is a path on the hillside.
AD = 800 m, DC = 600 m and CF = 200 m.
(a) Calculate the angle that the path AF makes with ABCD.
Answer(a) [5]
(b) In the diagram D is due south of C.
Jasmine walks down the path from F to A in bad weather. She cannot see the path ahead.
The compass bearing she must use is the bearing of A from C.
Calculate this bearing.
Answer(b) [3]
i am not that good at sets soo im really sorry pal
Q16a) its basically similarity
.125/64 = (x/8) cube
its a basic known this when its a volume its --> volume A/ volume B = (length or height A / length or height B) cube the bracket
and the same for area only u sq. it not cube it :D
Q21) a) Wht their asking for it FAC
sq. root (800sq+600sq) = 1000
Tan Q= 200/1000
Q = 11.3
b) ok work with me cause this is really difficult ....
i put up an image to help u image ... sorry if its messy ... ill just do the working here ... hope u under stand
we can do tan cause we need angle DCA
tan Q = 800/600
Q = 53.13
add 180 to that cause they want the bearing ... so its adds up to 233.13
Post by: Christy on May 09, 2009, 07:44:25 pm
here :)
Post by: Christy on May 09, 2009, 07:46:13 pm
Hey guys I did this MCQ paper and I got everything EXCEPT this question. I really don't understand why the answer is C. I thought the answer was D. Thanks in advance!
P.S. I have attacehd this particular question if you haven't noticed yet!
i think its C just a guess and a hunch :P
Post by: hyebyekadal on May 09, 2009, 08:11:18 pm
Post by: Zain-Xa on May 09, 2009, 08:11:52 pm
Q) Sarah has a set of holiday photographs (fewer than hundred) which she is going to put into a photograph album.
If she puts 2 photgraphs on each page, she will have 1 photograh left over.
If she puts 3 photgraphs on each page, she will have 2 photograh left over.
If she puts 4 photgraphs on each page, she will have 3 photograh left over.
If she puts 5 photgraphs on each page, she will have 4 photograh left over.
How many photgraphs does she have altogether?
plz help ASAP !!
Thanks in adv. ;D
Post by: hyebyekadal on May 09, 2009, 08:27:13 pm
Q 36 in the attached paper why is the correct answer D? Shouldn't it be C? When the resistance increases whys does the p.d. increase?
Again thanks in advance!!
Post by: hyebyekadal on May 09, 2009, 08:28:31 pm
Q 36 in the attached paper why is the correct answer D? Shouldn't it be C? When the resistance increases whys does the p.d. increase?
Again thanks in advance!!
Opps! Forgot to upload paper! Here!
Post by: hyebyekadal on May 09, 2009, 08:32:03 pm
Post by: Zain-Xa on May 09, 2009, 08:49:33 pm
Post by: astarmathsandphysics on May 09, 2009, 09:05:37 pm
Maths:From 1st condition ther number is odd andfrom las condition the last digit is 4 or 9 so must be nine sin the number is odd, so it must be 9,19,29,39,49,59,69,79,89,99. It has remainder 2 when dibided be 3 and remainder 3 when divided by 4.
Q) Sarah has a set of holiday photographs (fewer than hundred) which she is going to put into a photograph album.
If she puts 2 photgraphs on each page, she will have 1 photograh left over.
If she puts 3 photgraphs on each page, she will have 2 photograh left over.
If she puts 4 photgraphs on each page, she will have 3 photograh left over.
If she puts 5 photgraphs on each page, she will have 4 photograh left over.
How many photgraphs does she have altogether?
plz help ASAP !!
Thanks in adv. ;D
The answer is 59
Post by: godfather93 on May 09, 2009, 09:12:47 pm
Post by: hyebyekadal on May 09, 2009, 09:13:23 pm
Post by: hyebyekadal on May 09, 2009, 09:13:57 pm
Post by: Zain-Xa on May 09, 2009, 09:17:35 pm
Post by: godfather93 on May 09, 2009, 09:20:18 pm
Hopefully you get it now.
Post by: astarmathsandphysics on May 09, 2009, 09:20:44 pm
Guys one more question !!!
Q 36 in the attached paper why is the correct answer D? Shouldn't it be C? When the resistance increases whys does the p.d. increase?
Again thanks in advance!!
Opps! Forgot to upload paper! Here!
The answer is D We have a potential divider. The LDR is a semiconductor and the resistance goes up in the dark because less electrons move into the conduction band. VLDR=VRLDR/(R+RLDR) and VLDR increases with |RLDR
Post by: Zain-Xa on May 09, 2009, 09:24:40 pm
Post by: hyebyekadal on May 09, 2009, 09:24:59 pm
Post by: sweetsh on May 09, 2009, 09:25:12 pm
Post by: sweetsh on May 09, 2009, 09:25:54 pm
Thank You! + rep!@!!!!There is a rule in the forum not to ask anyone for icreasing your rep.
Post by: godfather93 on May 09, 2009, 09:28:05 pm
Post by: hyebyekadal on May 09, 2009, 09:28:33 pm
Ps. sweetsh you got me wrong I was talking to astar and god father as I increased THEIR rep because they just helped me!
not asking to increase mine!
Post by: sweetsh on May 09, 2009, 09:29:58 pm
Post by: Zain-Xa on May 09, 2009, 09:31:36 pm
zainy ur q is kind of hard to explain look at the problem again when you divide by 4 you get reminder of 3 so 59/4 =14 and 3 reminder same with dividing with 3 you get reminder of 2! 59-2 =57/3=19
Ps. sweetsh you got me wrong I was talking to astar and god father as I increased THEIR rep because they just helped me!
not asking to increase mine!
oooh kk i got it now Thanks a lot ;D to u and astar... ;D
Post by: godfather93 on May 09, 2009, 09:33:11 pm
Post by: astarmathsandphysics on May 09, 2009, 09:33:44 pm
i got the first part by i dont get wt u divide by 2 to get the remainder 3... etc. ???
Which condition?
Post by: godfather93 on May 09, 2009, 09:35:09 pm
Post by: sweetsh on May 09, 2009, 09:35:38 pm
Post by: Zain-Xa on May 09, 2009, 09:35:57 pm
and the year is frm nov 1990 last question
Post by: godfather93 on May 09, 2009, 09:36:47 pm
Post by: Zain-Xa on May 09, 2009, 09:37:48 pm
Post by: godfather93 on May 09, 2009, 09:38:39 pm
He quoted Zainy
sorry, did not see the quote. :-[
Post by: sweetsh on May 09, 2009, 09:48:41 pm
Post by: Zain-Xa on May 09, 2009, 09:57:20 pm
A student played a computer game 500 times and won 370 of these games.
he then won the next "x" games and lost none.
he has now won 75% of the games he has played.
Find the value of "x"
(pls show hw u got ur answer)
Post by: zara on May 09, 2009, 10:02:52 pm
total games played=500+x
games won=370+x
therefore,,,
370+x=(75/100)(500+x)
370+x=375+0.75x
375-370=x-0.75x
5=0.25x
x=5/0.25
x=20
chk d answer wid ms n if its rong lemme kno....
nemor doubts...plz don't hesitate ;)
Post by: godfather93 on May 09, 2009, 10:05:13 pm
the number of games he's won is 370 + x
The number of games he has won is 75% of (500 + x). (cause it says that he won 75% of the total games played)
hence, 370 + x = 75/100 * (500 + x)
370 + x = 375 + 0.75 x
0.25x = 5
x = 20
Post by: godfather93 on May 09, 2009, 10:05:50 pm
Post by: zara on May 09, 2009, 10:07:06 pm
Post by: zara on May 09, 2009, 10:07:59 pm
Post by: Zain-Xa on May 09, 2009, 10:12:25 pm
Post by: Zain-Xa on May 09, 2009, 10:15:04 pm
a straight line passes through 2 points with co-ordinates (6,8) and (0,5).
Equation of the line??????????
Post by: astarmathsandphysics on May 09, 2009, 10:20:39 pm
My last Q for now :P
a straight line passes through 2 points with co-ordinates (6,8) and (0,5).
Equation of the line??????????
gadient m=(y2-y1)/(x2-x1)=(5-8)/(0-6)=1/2
y-y1=m(x-x1)
y-8=1/2(x-6) so y=1/2x+5
Post by: godfather93 on May 09, 2009, 10:21:51 pm
so it's (8 - 5)/(6-0)= 1/2
the y intercept is 5 because of the coordinate (0,5)
equation of line = y= 1/2x + 5
Post by: godfather93 on May 09, 2009, 10:22:48 pm
Post by: astarmathsandphysics on May 09, 2009, 10:24:02 pm
Post by: godfather93 on May 09, 2009, 10:24:33 pm
Post by: Zain-Xa on May 09, 2009, 10:26:56 pm
Post by: godfather93 on May 09, 2009, 10:27:50 pm
Post by: astarmathsandphysics on May 09, 2009, 10:28:03 pm
Post by: zara on May 09, 2009, 10:28:24 pm
Post by: Zain-Xa on May 09, 2009, 10:35:23 pm
Post by: love on May 10, 2009, 07:58:04 am
f-1(x)=root of x
i.e if x =2 den f(x)=100
f-1=10
so d ans u wud get after solving wud equal 0
root of 10
Post by: Christy on May 10, 2009, 08:00:39 am
f(x)= 10^x
f-1(x)=root of x
i.e if x =2 den f(x)=100
f-1=10
so d ans u wud get after solving wud equal 0
root of 10
wow im confused :S
Post by: astarmathsandphysics on May 10, 2009, 08:09:57 am
f(x)= 10^x
f-1(x)=root of x
i.e if x =2 den f(x)=100
f-1=10
so d ans u wud get after solving wud equal 0
root of 10
y=10x so log10y=x now swap x and y over y=log10x and f-1x=log10x
Post by: Christy on May 10, 2009, 08:13:17 am
i no its in the calculator but wat do u use it for ??
and ... please can someone explain wat astar and love are talking about cause they are making me nervous ...
more likely explain in baby steps
Post by: SGVaibhav on May 10, 2009, 08:14:04 am
it sounds so much fun!!
Post by: Christy on May 10, 2009, 08:16:37 am
i wish my school would have offered additional mathematics.
it sounds so much fun!!
WOW ..... u wish tht ... ull be entering in ur worse nightmare ... more like digging ur own grave :D
jokes :)
Post by: SGVaibhav on May 10, 2009, 08:17:56 am
Post by: astarmathsandphysics on May 10, 2009, 08:18:22 am
Post by: godfather93 on May 10, 2009, 08:18:57 am
Post by: love on May 10, 2009, 08:24:36 am
in inverse
division becomes multiplication and vice verse
addition becomes substraction and vice verse
same way
square becomes square root
got...ya nahi
so f(x)=10^x become f-1(x)= square root of 10
Post by: godfather93 on May 10, 2009, 08:27:34 am
Post by: love on May 10, 2009, 08:30:10 am
log is not taught to u man!!!!
Post by: astarmathsandphysics on May 10, 2009, 08:31:50 am
Log is totally different.
I am surprised it is in igcse
Does your calculator has a solve or calc button?
Post by: godfather93 on May 10, 2009, 08:34:36 am
Post by: astarmathsandphysics on May 10, 2009, 08:35:52 am
Post by: love on May 10, 2009, 08:37:43 am
n our teacher asked us not use log
ok fi9 by d way tell whts LOG???
Post by: godfather93 on May 10, 2009, 08:38:29 am
Post by: astarmathsandphysics on May 10, 2009, 08:41:01 am
Post by: love on May 10, 2009, 08:41:24 am
Log is like asking if 5=10x what is x? It is log105/log1010 or ln5/ln10
ok thx dear...
Post by: SGVaibhav on May 10, 2009, 09:11:45 am
THIS IS THERE IN THE SYLLABUS
UR SHOCKED RIGHT!!!
IT IS THERE IN ADDITIONAL MATHEMATICS SYLLABUS
Post by: emi on May 10, 2009, 10:12:09 am
can u solve this one by log ?
(a) Simplify (27x6)1/3
(b) (512)-2/3 = 2p
. Find p.
Post by: Zain-Xa on May 10, 2009, 10:21:59 am
for e.g 2=5^x then u can use log
x = log2/log5
Post by: Zain-Xa on May 10, 2009, 10:23:32 am
log log(512)^-2/3 / log 2
Post by: SGVaibhav on May 10, 2009, 11:27:23 am
i dont know all this log
Post by: Christy on May 10, 2009, 11:32:28 am
u shudve seen my face wen i new about this :P
Post by: emi on May 10, 2009, 06:13:04 pm
m/j 2003 paper 6 physics Q4 part a ii) and b .... please im waiting
Post by: godfather93 on May 10, 2009, 06:44:12 pm
a ii) for part a i) you must have measured the length (x) of the string. If you read the question carefully, it says that this piece of string was used to wrap around the pin 10 times. So to find the circumference of the pin, you just divide the length by 10 to get the circumference of the pin.
Post by: emi on May 10, 2009, 07:03:06 pm
if any one could tell me how to do
m/j 2003 paper 6 physics Q4 part a ii) and b .... please im waiting
can any one also do O/N 2003 Q1 part d ??? please ..Pleeeaaaseeeee i need these
Post by: Christy on May 10, 2009, 07:29:56 pm
just check tht
and the answer to ur q.
they are asking u to estimate ... basically just guess
ur answer will be a bit less than ur answer in c
Post by: godfather93 on May 10, 2009, 07:39:02 pm
Astar, pleasse help!
Post by: sweetsh on May 10, 2009, 07:42:40 pm
Post by: godfather93 on May 10, 2009, 08:03:36 pm
Post by: godfather93 on May 10, 2009, 08:04:37 pm
Post by: emi on May 10, 2009, 08:18:07 pm
Post by: sweetsh on May 10, 2009, 08:20:07 pm
Post by: june on May 10, 2009, 09:09:03 pm
Post by: sweetsh on May 10, 2009, 09:09:53 pm
Post by: godfather93 on May 10, 2009, 10:32:58 pm
it's question 6, paper is attached. (it's maths)
Thanks
I don't get it, the ms says it's 96km/hr and i get 48km/hr. ???
Post by: godfather93 on May 10, 2009, 10:37:40 pm
Post by: astarmathsandphysics on May 10, 2009, 10:41:03 pm
help needed urgently!distance/time=80km/50mins=80km/(5/6hr)=96km/hr
it's question 6, paper is attached. (it's maths)
Thanks
I don't get it, the ms says it's 96km/hr and i get 48km/hr. ???
Post by: sweetsh on May 10, 2009, 10:42:54 pm
Post by: godfather93 on May 10, 2009, 10:46:08 pm
Post by: astarmathsandphysics on May 10, 2009, 10:56:10 pm
Post by: godfather93 on May 10, 2009, 10:59:11 pm
Post by: SGVaibhav on May 11, 2009, 07:04:04 am
:P
u have to find the speed in km/h
while in graph, the time is in minutes
so u ahve to convert it into hours
to convert 50 mins into hours
50/60 = 5/6
speed = dist/time
=80/(5/6)
=80 x 6/5
=480/5
=96km/h
Post by: Ukhti-R on May 11, 2009, 07:34:12 am
I cant do Q20a,c i) and ii)
May june 2008 P2
anyone ..?
Post by: astarmathsandphysics on May 11, 2009, 07:40:19 am
Im stuck guyz
I cant do Q20a,c i) and ii)
May june 2008 P2
anyone ..?
ci)Times the area by (103)2= 106
ii)Divide your answer toci) by 1.5
Post by: Ukhti-R on May 11, 2009, 07:45:01 am
cuz, its mcube to mm cube
soisnt that 100x100x100x10x10x10 ?
and for a) I did (95/360x piex160x160)-(95/360xpiex100x100)
but Im getting it rong...
:(
Post by: Ukhti-R on May 11, 2009, 08:04:27 am
Post by: astarmathsandphysics on May 11, 2009, 08:09:14 am
astar? u there ?1m3=(1000mm)3=1000000000mm3
Yes you are right
Post by: Ukhti-R on May 11, 2009, 09:08:11 am
because Im getting a different answer than the mark scheme
Post by: tmisterr on May 11, 2009, 09:11:25 am
Post your IGCSE questions here to get the answers back asap from someone with 3 maths/physics degrees.hey astar i need help with question 2(a), the circuit drawing. The paper is OCT/NOV 2005 physics paper 6
Post by: Ukhti-R on May 11, 2009, 09:12:38 am
so.. how do you do Q10 a P2 1998 ??
Post by: Kim on May 11, 2009, 09:22:09 am
A drinking straw was sealed at one end with candle wax.tyhe straw was made to float upright in water by putting a small amount of ballast into the straw.The height of the top of the straw was determined uysing a set square attached to the meter rule..The height was h
a-explain why the set square is used when taking the reading for h
b-before taking the readings for h, one of the students pushed the straw down a little.the straw then moved up and down befor coming to rest.suggest a reason why this was done.
c-the straw floats in the water so dat its top is as high as possible.For this reason the container was full of water.Suggest what would happen if the container was not quite full i.e it was three quarters full
HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Post by: astarmathsandphysics on May 11, 2009, 09:26:14 am
ok i m kind of worried i need an answer to an old paper6 physics question year 1999a)to make the height reading accurate
A drinking straw was sealed at one end with candle wax.tyhe straw was made to float upright in water by putting a small amount of ballast into the straw.The height of the top of the straw was determined uysing a set square attached to the meter rule..The height was h
a-explain why the set square is used when taking the reading for h
b-before taking the readings for h, one of the students pushed the straw down a little.the straw then moved up and down befor coming to rest.suggest a reason why this was done.
c-the straw floats in the water so dat its top is as high as possible.For this reason the container was full of water.Suggest what would happen if the container was not quite full i.e it was three quarters full
HELP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
b) to reduce the effect of surface tension
c)It might touch the bottom and tilt over
Post by: Kim on May 11, 2009, 09:36:36 am
rays of light are reflected from the poutside of a beaker that contained siome water coloured with blue ink
a- why is it an advantage to fill the the beaker with coloured water when viewing the lamp by a ray reflected from the outside surface of the beaker?
in some questions they tell that three lamps are connected in parallel and a voltmeter connected to record the potential difference across all three lamps
where do i put the voltmeter?their is also a variable resistor to vary the brightness of all the 3 lamps
Post by: hyebyekadal on May 11, 2009, 10:47:23 am
with each other have a smaller combined resistance than the two lamps in series. Draw
one circuit diagram showing
(i) two lamps in parallel with each other connected to a power source,
(ii) an ammeter to measure the total current in the circuit,
(iii) a voltmeter to measure the potential difference across the two lamps.
Help? Can anyone be kind enough to draw and show how the circuit diagrams for these kind of questions should look?
Also I particularly need help with the part (iii) as how can you connect a voltmeter to measure the voltage across BOTH the lamps?
Thanks in advance and I hope that someone will answer this question soon!
Post by: emi on May 11, 2009, 11:10:23 am
Post by: emi on May 16, 2009, 10:19:42 am
http://www.freeexampapers.us/IGCSE/Maths/CIE/Specimen/0580_y11_sp_4a.pdf
Post by: cockyxrocker on May 16, 2009, 11:48:32 am
feel free to ask if u have any doubts ^^
Post by: emi on May 16, 2009, 01:24:39 pm
u have been great help to me .. i really appreciate the time u spent to make that ... thanks alot :-*
Post by: Zakoor on May 23, 2009, 11:21:54 pm
On the IGCSE syllabus (code 0625) physics, 3.1 , it says that we have to "give the meaning of the term wavefront"
Can anyone explain and define wavefront? Cause Ive tried reading it from a book but don't seem to understand what its about exactly.
Thanks.
Post by: astarmathsandphysics on May 23, 2009, 11:25:29 pm
Post by: Zakoor on May 23, 2009, 11:34:08 pm
A crest.
Don't understand what you mean exactly, Any further explanation? ???
Post by: nid404 on May 24, 2009, 06:15:51 am
read this page http://jcsu.jesus.cam.ac.uk/~rpc25/notes/physics/waves/waves.html
i'm not very good at explaining
Post by: SGVaibhav on May 24, 2009, 08:23:17 am
will be back in 2 minutes, giving the link
Post by: SGVaibhav on May 24, 2009, 08:25:10 am
here this is a very kool transformer
anyone knows a website, wherer we can play with a cro. like we connect the y plates and we adjust the grid and ..
Post by: Zakoor on May 24, 2009, 09:53:27 am
Post by: studentforumuser on June 02, 2009, 12:07:46 pm
So Can Someone plzz Tell me the most important things, you should know for PHYSICS, ???
like things whuch are really important.. MESSAGE ME ..plzz :'(
Thanks Anyway..! :P
=D
::)
does any1 have a summary or any notes etc.... like the one q80boy had given for chemistry..!!
just put it up here pls..! :)
Post by: Kim on June 03, 2009, 12:10:49 pm
Post by: Ghost Of Highbury on June 03, 2009, 12:17:06 pm
Hey,this guid was given to me by nid404
So Can Someone plzz Tell me the most important things, you should know for PHYSICS, ???
like things whuch are really important.. MESSAGE ME ..plzz :'(
Thanks Anyway..! :P
=D
::)
does any1 have a summary or any notes etc.... like the one q80boy had given for chemistry..!!
just put it up here pls..! :)
thank her
good luck
Post by: AAR on May 04, 2012, 11:57:22 am
anyone with igcse maths paper 2 specimen paper 2012 ??
thank u :)
Post by: lollypop on May 19, 2012, 09:59:52 pm
Post your IGCSE questions here to get the answers back asap from someone with 3 maths/physics degrees.Oct/nov 01 p3 Q8 part b - can anyone pls help me with this question?
Post by: MalloryKnox on September 11, 2012, 01:50:46 pm
Post by: The Golden Girl =D on September 11, 2012, 10:25:34 pm
I'm taking Maths Modular GCSE, and my first module which is Statistics and Probability. I know most of the stuff, but I was wondering if you could give me some notes on a Cumulative Frequency histogram? Thanks! ???
Next time post in this THIS (https://studentforums.biz/index.php?topic=10006.0) thread please for any further math inquiries =)
Here are some links that I hope you find useful ;
http://www.gcsemathstutor.com/cumulativefreq.php
http://www.astarmathsandphysics.com/igcse_maths_notes/igcse_maths_notes_cumulative_frequency_curves_quartiles_interquartile_range_and_median.html
http://www.mathsrevision.net/alevel/pages.php?page=71
http://www.youtube.com/watch?v=4W7Z-QkGz2Q
http://www.gcsemathstutor.com/histograms.php
I hope I helped :)
Post by: MalloryKnox on September 13, 2012, 09:30:27 am
Thanks so much! that's really helpful!!
Post by: The Golden Girl =D on September 13, 2012, 12:16:06 pm
You're welcome :D
Post by: MalloryKnox on September 13, 2012, 01:59:54 pm
Post by: MalloryKnox on October 03, 2012, 01:52:33 pm
Oct/nov 01 p3 Q8 part b - can anyone pls help me with this question?Send the paper link? :)
Post by: astarmathsandphysics on October 03, 2012, 02:35:56 pm