Physics: Post your doubts here!

[Unicorn]

Can someone please explain how to do q30
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w11_qp_13.pdf

because that is not on the AS syllabus

I have found a site to help me but I don't get anything from it
http://www.physicsclassroom.com/Class/sound/u11l5d.cfm equation for closed end tube: f=v/4l
http://www.physicsclassroom.com/class/sound/u11l5c.cfm equation for open end tubes: f=v/2l

does the frequency have to be like greater than 0.5 for stationary waves??

 

[raamish]

honey are you ok? there is still no 4b(iv)

yeh honey im ok. the problem here is that even though i changed the ppr from w10 to w11 it was still opening the previous paper. just go to the adressbar and change it to w11

 

[Idolfanatic95]

for question 2 you have
accn = 2.5 x10^15
time = 2.4 x10^-9
intial speed= 5 x10^7

and u know that the electron is launched halfway between the plates so the distance between it and the plate is 1.5/2 =0.75

using equation of motion= s= ut +(at^2)/2 you get s to be 0.1272 which is much less than 0.75 so no it does not hit it

for question 4 ur diagram is probably wrong draw it again

I drew again. didn't get anywhere close to 41-48 :s cud u draw it for me?

 

[confused123]

how to solve log questions in some physics practical papers...

 

[robotic94]

Ok View attachment 10429

as you can see from the diagram I rearranged the forces but didn't change the direction
the angle between T1 and T2 is 90 because T1 is at an angle of 50 to horizontal and T2 at 40 to horizontal
and the angle between 7.5N and t=T1 is 40 because it is vertically downwards so is perpindicular to horizontal

to find T1 and T2 use trignometery

hope it helped

Yes i got it now
Tysm

 

[robotic94]

paper please

oh sorry!
http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w11_qp_23.pdf

 

[Unicorn]

I drew again. didn't get anywhere close to 41-48 :s cud u draw it for me?

don't have a camera right now to upload it to you sorry :\

 

[Unicorn]

oh sorry!
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w11_qp_23.pdf

what do u mean by v?? are youn sure it is 1c ii ?

 

[robotic94]

what do u mean by v?? are youn sure it is 1c ii ?

Jeez
i am so sorrry!
q2 it is!

 

[Idolfanatic95]

don't have a camera right now to upload it to you sorry :\

ok nvm

 

[Unicorn]

yeh honey im ok. the problem here is that even though i changed the ppr from w10 to w11 it was still opening the previous paper. just go to the adressbar and change it to w11

so nov 2011 23?

 

[Unicorn]

Jeez
i am so sorrry!
q2 it is!

ok so using the equation v^2=u^2 +2as

for intial state (v would be zero and zero squared is zero so i will leave it out to make it easier to calculate)
so distance will be -u^2/2a =s

for half speed u= 0.5u therefore -> -(0.5u)^2/2a =s' (s' is the unknown distance)
simplyfy equation u get -1/4 *u^2 which is basically -u^2/4/2a which gives -u^2/8a =s'

when ever you have a situation like the above divide the thing you are trying to find by original
ie s'/s = (-u^2/2a) /(-u^2/8a) which gives s'/s =2/8 so s'= 0.25 s

hope it helped

 

[confused123]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s09_qp_32.pdf
q.2 e part related to constants k..which formula for k to be used.....

what about the questions which ask us to justify the number of significant fugues we have to state...?

 

[shaadhir]

http://www.physicsclassroom.com/Class/waves/

hey thanx =)

 

[shaadhir]

http://www.s-cool.co.uk/a-level/physics
Try this

in that site u gave the pictures are not appearing it is asking for a adobe flash player but i do have the latest version wat am i to do

 

[darknessinme]

Can someone please explain how to do q30
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w11_qp_13.pdf

because that is not on the AS syllabus

I have found a site to help me but I don't get anything from it
http://www.physicsclassroom.com/Class/sound/u11l5d.cfm equation for closed end tube: f=v/4l
http://www.physicsclassroom.com/class/sound/u11l5c.cfm equation for open end tubes: f=v/2l

does the frequency have to be like greater than 0.5 for stationary waves??

They wouldn't set a question outside of the syllabus. You just need to apply your knowledge to the situation.
What you need to do is find out if you can draw a stationary wave in both the tubes P and Q. If you are able to draw a stationary wave in a tube, then a stationary wave can be formed in it.
Closed end of a pipe is always a node, and the open end is always an anti-node.
For P you have an anti-node at the open end, and a node at the closed end. You are able to draw a stationary wave 35cm long with 4 nodes, and 4 anti-nodes so P works.
For Q, both ends have an anti-node. You are able to draw a stationary wave 50cm long with 5 nodes, and 6 anti-nodes, so Q works too.
Final answer is A!

 

[raamish]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s05_qp_2.pdf

4c) dont understand the markign scheme plzz xplain

 

[Idolfanatic95]

in that site u gave the pictures are not appearing it is asking for a adobe flash player but i do have the latest version wat am i to do

Pictures do appear, ive been viewing 'em. prolly refresh or sumthing :s

 

[Henry930821]

Hey people i have an important question.. Does number of significant figures matter in phy paper 2? If answer scheme gives 2sf for final answer but i gave in 3sf, do i lose any mark?

 

[Soldier313]

i just read something about simple harmonic motion and was wondering is that covered in our AS Physics syllabus?