Discussion for physics P-21 CIE here!

[leebux101]

i am just making this thread so tht we can all discuss it at one place...but after 24 hours please...
i dont wna be banned by the moderators aka drill sergeants ... lol!   

[leebux101]

so are 24hours over yet?

[Chingoo]

Yes, they are.

[leebux101]

ok guys lets discuss!!
how was it? confusing, tricky, demanding..ur worst nightmare...lol
i got confused where they asked for the equation relatinc v1 and v2 for momentum...but i managed somehow....

[mr.incredible]

ok guys lets discuss!!
how was it? confusing, tricky, demanding..ur worst nightmare...lol
i got confused where they asked for the equation relatinc v1 and v2 for momentum...but i managed somehow....

Well, for me it was a bit confusing and i am very afraid that the grade thresholds might be so high  !!!

This was one of the questions that confused me somehow, anyways what were your answers to the two equations and the trolley with the greater kinetic energy.

I hated the question of the diffraction grating being rotated parallel to the beam  .

[leebux101]

first equation... m1/m2 = v2/v1
second equation... e = 0.5mv^2 + 0.5mv^2

i did trolley b for the lesser KE..

for the diffraction grating... i did tht they will form in a horizontal plane..


i am not sure abt any of these answers though..lets see what pthers think...

[mr.incredible]

first equation... m1/m2 = v2/v1
second equation... e = 0.5mv^2 + 0.5mv^2

i did trolley b for the lesser KE..

for the diffraction grating... i did tht they will form in a horizontal plane..


i am not sure abt any of these answers though..lets see what pthers think...

First equation m1v1=m2v2  (conservation of momentum), your equation is correct although i don't know how did you get it in such way !

Second equation, same like you.

I chose the trolley with the least mass for greater kinetic energy as it will have greater speed and Ke= 0.5 m"v^2"

[leebux101]

yeah that was trolley b. it had lesser mass

abt the firsy equation...i wrote wut u wrote and then put it as a ratio...
r u sure abt the second equation though?

[leebux101]

does anyone have other ideas?

[sweetie]

for the grating Que. i wrote that the positions of X,Yor P wont change!!!

nd about the power Q. will it decrease or increase?
i wrote it will decrease.....

[leebux101]

for the power question : power was double so it increased..

[leebux101]

r u sure abt the answer for the grating question...

[sweetie]

r u sure abt the answer for the grating question...

nooo

[sweetie]

for the power question : power was double so it increased..

but they said that the length waz halved , so voltage waz also halved so power halves since current remains constant (P=VI)
newayz, am not sure about it, so lets c...

[leebux101]

i did the calculations and stuff... i got power as 120 which is twice the previous value of 60
...not sure though...
lets see what others think..