IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => IGCSE/ GCSE => Sciences => Topic started by: MissDE on May 11, 2009, 07:17:25 am

Title: Physics
Post by: MissDE on May 11, 2009, 07:17:25 am


What's the triangle method for finding the gradient...??
Title: Re: Physics
Post by: SGVaibhav on May 11, 2009, 07:18:36 am
lol  i just asked that in one of the posts before 1 min
Title: Re: Physics
Post by: MissDE on May 11, 2009, 07:19:46 am

hehe :D

We think the same way  ;)
Title: Re: Physics
Post by: Ukhti-R on May 11, 2009, 07:20:24 am
Triangle method ?
wots that?
is it y2-y1/x2-x1 ??
thats how you find the gradient of a line.. but a triangle method... ???
Title: Re: Physics
Post by: MissDE on May 11, 2009, 07:21:54 am


I knw..

But if you check the mark scheme...

there are marks for using it ... (I tried ur way and it gives the same answer as the mark scheme but the way is different)
Title: Re: Physics
Post by: Christy on May 11, 2009, 08:34:45 am
wat r u talking about the distance travelled ??

cause the only triangular method related to gradient or graph is

1/2 * base * height

which is the distance ...  ???

new things come up making me feel like im not prepared :S :S
Title: Re: Physics
Post by: astarmathsandphysics on May 11, 2009, 08:40:57 am
There is a triangular method for finding the gradient. Called ris by run or m=(y2-y1)/(x2-x1) You need it to find the velocity on a distance time graph or the acceleration on a velocity time graph.
PHEW!!!!!!!!! nOW I THINK I HAVE ANSWERED ALL THE QUESTIONS POSTED SINCE I LAST ANSWERED ALL THE QUESTIONS I COULD FIND.
Title: Re: Physics
Post by: Kim on May 11, 2009, 08:59:57 am
ok i m kind of worried i need an answer to an old paper6 physics question year 1999
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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ???
Title: Re: Physics
Post by: thisishard on May 11, 2009, 09:52:44 am
Kim: a) to ensure that it is perpendicular and avoid parallax error as the straw is far from the rule
       b) weight will balance the upthrust and then it will stop vibrating
       c) value of H would be lower

hope it helps  ;)
Title: Re: Physics
Post by: thisishard on May 11, 2009, 10:04:33 am
Got a question of my own :
Phyiscs paper 6 O/N 2007 question 1 ,c)i

sorry if considered spam
Title: Re: Physics
Post by: Christy on May 11, 2009, 10:45:25 am
no

it depends on the temp. of the surrounding
Title: Re: Physics
Post by: thisishard on May 11, 2009, 11:11:12 am
thanks:) another question :
 M/J 2008 paper 6 question 1) b
Title: Re: Physics
Post by: Q80BOY on May 11, 2009, 11:43:45 am
ok i m kind of worried i need an answer to an old paper6 physics question year 1999
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!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ???

(a) Because the straw is far from the metre rule, the set square is used to get an accurate reading a parallax error.

(b) The straw vibrates until the force of weight balances the upthrust force.

(c) The value of h measured would be lower than it should.

gd luck  ;)
Title: Re: Physics
Post by: astarmathsandphysics on May 11, 2009, 09:53:24 pm
Got a question of my own :
Phyiscs paper 6 O/N 2007 question 1 ,c)i

sorry if considered spam

Yes in the 1st min the temp fell 23 and in the last min 0.5