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Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: halosh92 on March 26, 2010, 08:31:39 pm

Title: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 26, 2010, 08:31:39 pm
 an isolated body can be a given a displacement or a rotation. what is the result of applying a couple?
a) displacement
b) rotaion
c) displacement and rotation
d) neither
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: A.T on March 26, 2010, 08:57:53 pm
couple can surely rotate a body.
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 26, 2010, 08:59:26 pm
physics AS cie
2009 june
q2 b
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on March 26, 2010, 09:25:32 pm
but which paper
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 27, 2010, 06:42:06 am
Quote from: astarmathsandphysics on March 26, 2010, 09:25:32 pm
but which paper

ah sorry ya paper 2
question 2
the entire question not just part b
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on March 27, 2010, 07:08:52 am
a)positive v - moving forward negative v - moving backwards
b)i)m(v-u)=1.2(-0.8-4)=-5.76
ii)Force=change in momentum/time=5.76/(2.6-1.8)=7.2N
c)mAuA+mSuS=mAvA+mBvB
1.2*4+0=1.2*-0.8+3.6vS so (4.8+0.96)/3.6=1.6m/s
loss in KE=1/2mAvA^2 -1/2mBuB^2-1/2mAuA^2=1/2*1.2*4^2-1/2*1.2*0.8^2-1/2*3.6*1.6^2=9.6-0.385-4.608>0 so inelastic
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 27, 2010, 08:02:50 am
Quote from: astarmathsandphysics on March 27, 2010, 07:08:52 am
a)positive v - moving forward negative v - moving backwards
b)i)m(v-u)=1.2(-0.8-4)=-5.76
ii)Force=change in momentum/time=5.76/(2.6-1.8)=7.2N
c)mAuA+mSuS=mAvA+mBvB
1.2*4+0=1.2*-0.8+3.6vS so (4.8+0.96)/3.6=1.6m/s
loss in KE=1/2mAvA^2 -1/2mBuB^2-1/2mAuA^2=1/2*1.2*4^2-1/2*1.2*0.8^2-1/2*3.6*1.6^2=9.6-0.385-4.608>0 so inelastic

thx aloot
but wats the basic general formula for K.E ?
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on March 27, 2010, 08:05:52 am
KE=1/2mv^2
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 27, 2010, 08:42:22 am
 what is maxima and minima in the waves chapter
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 27, 2010, 08:53:44 am
same paper
2009 june paper 2
q5 the whole question

q7 ..plz expalin wat do they mean by exactly BETWEEN??

and for the minima and maxima is there a formula??
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on March 27, 2010, 10:16:45 am
Home in few hours
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on March 27, 2010, 12:25:39 pm
Quote from: astarmathsandphysics on March 27, 2010, 10:16:45 am
Home in few hours

okay but plzz i need today i have my mock tomorrow
thxxx
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on March 27, 2010, 01:38:58 pm
When I post like that I am reminding myself  to answer asap
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on March 27, 2010, 02:28:22 pm
q5 here https://studentforums.biz/index.php/topic,6323.0.html

By in between they mean the resistance between the points
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 04, 2010, 08:07:33 pm
is any one doin AS edexcel physics
i need extra resources preferably notes related to unit 2
Thanks
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: Saladin on April 04, 2010, 08:14:45 pm
what notes in particular??

i have loads.
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 04, 2010, 08:19:06 pm
hi
is any one doing AS edexcel physics ???
if so i would really appreciate if you can post some good physics notes or atleast a good website
other than astarmathandphysics as i have already gone through it
Thanks  :)
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: Saladin on April 04, 2010, 08:21:59 pm
of all the sites, that i have been to, this is by far the best....


S-cool A LEVEL PHYSICS (http://www.s-cool.co.uk/alevel/physics.html)
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 04, 2010, 08:35:27 pm
hi is any one doing AS level physics(edexcel)

As i need any unit 2 physics notes i can get my hands on, and if ther e are any other good websites besides astarmathandphysics  as i have already gone thru it my mocks r comin up so please hurry
 
Thanks
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 04, 2010, 08:38:36 pm
umm sry bout all ma annoyin mesg smethin wrong wid net

any notes on electricty, waves ,and quantum would do
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: Saladin on April 04, 2010, 08:46:21 pm
the website that i gave u has all that u will ever want.

i study completely from there.
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 06, 2010, 08:05:13 pm

help needed
Can sme1 explain to me Q17b,c in the 6ph02 2010 paper
hurry
i need an explanation 4 the ans. i dont understand it  :'(
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 06, 2010, 09:19:06 pm
can sme 1 ans my doubt please

i also need help in this question:
Explain why the minima never has a zero value ?
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 07, 2010, 10:00:45 am
people i need sme 1 to explain the questions  i asked
my mocks r v.close
help needed  ??? :'(
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: nid404 on April 07, 2010, 10:15:24 am
is this cie or edexcel
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on April 07, 2010, 10:19:39 am
1 hour
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on April 07, 2010, 11:17:02 am
b)Number of charge carriers much smaller for silican so they must move faster
c)when temp increases resistance decreases as for all semiconductors
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 07, 2010, 11:30:52 am
Thanks

and its an edexcel paper
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on April 07, 2010, 06:36:31 pm
physics cie
AS
mayjune 2008
q 4c

in the ms....there is 4.7
where did they get it from
plz someone hurry up!
thx
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: nid404 on April 07, 2010, 06:52:46 pm

 1.01 × 105 Pa=Hx X 1.08 × 103 X 9.8
H=9.53m

change in h= 10-9.53=0.47

dh/h=0.47/10 X100 = 4.7%
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on April 07, 2010, 07:01:08 pm
Quote from: nid404 on April 07, 2010, 06:52:46 pm
1.01 × 105 Pa=Hx X 1.08 × 103 X 9.8
H=9.53m

change in h= 10-9.53=0.47

dh/h=0.47/10 X100 = 4.7%

okeks thankyou os much :)))))
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: nid404 on April 07, 2010, 07:04:58 pm
ur welcome
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: halosh92 on April 07, 2010, 07:21:32 pm
the same paper
q6 b part
could u explain how to find the power here?
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: nid404 on April 07, 2010, 07:34:19 pm
https://studentforums.biz/index.php/topic,5940.msg173140/topicseen.html#msg173140
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 07, 2010, 08:43:21 pm
can sme 1 plz ans my ques about the maxima not havin a value 0
 >:( >:( >:(
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: astarmathsandphysics on April 07, 2010, 11:33:12 pm
Is it because they are not completely out of phase or not having the same amplitude?
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: nid404 on April 08, 2010, 06:55:37 am
MAxima  is due to constructive interference which means waves are in phase.......
the sum of the amplitudes in this case will never be equal to zero....
Title: Re: physics doubts VERY URGENT!!!!!!!!!!!!
Post by: AS panic attack on April 08, 2010, 08:59:53 am
ummm imade a mistake
i wanted an explanation on why the minima never has a zero value
srry