Qualification > Sciences
A-Level Physics Paper 1 doubts (MCQ)
Ghost Of Highbury:
--- Quote from: Ari Ben Canaan on June 04, 2011, 09:38:30 am ---Give me some time.
--- End quote ---
Sure, thanks a lot
elemis:
I've done the sketch below. The dotted curve represents the wave a few seconds later in time.
Notice all the points except C have moved downwards.
Ghost Of Highbury:
--- Quote from: NidZ- Hero on June 04, 2011, 09:25:41 am ---Kinda figure that out so the answer is A ..
N that momentum question can yu pls show the working
--- End quote ---
Total Ke b4 collision => 0.5*2m*u^2 + 0.5*m*(-u)^2 = mu^2 + mu^2/2 = 3/2 mu^2
Total momentum b4 => 2mu - mu = mu
A. KE after collision -> 0.5*2m*(u/3)^2 + 0.5*m*(5u/3)^2 = mu^2 /9 + 25mu^2/18 = 3/2 mu^2
Momentum = 2m*(-u/3) + m*(5u/3) = 5mu/3 - 2mu/3 = 3mu/3 = mu
Ghost Of Highbury:
--- Quote from: Ari Ben Canaan on June 04, 2011, 09:43:28 am ---I've done the sketch below. The dotted curve represents the wave a few seconds later in time.
Notice all the points except C have moved downwards.
--- End quote ---
Okay, thanks, but how does it show that at that point the wave is moving UPWARDS with MAXIMUM speed?
elemis:
--- Quote from: Ghost Of Highbury on June 04, 2011, 09:47:29 am ---Okay, thanks, but how does it show that at that point the wave is moving UPWARDS with MAXIMUM speed?
--- End quote ---
If you draw a straight vertical line through point A, the point where the line intersects with the dotted curve is the point at which A is later on in time.
Notice, point A will have moved downwards.
Do the same with the rest. Only C moves upwards.
Additionally, C moves the greatest distance in the same time as the rest. Velocity = distance/time
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version