Question

Use the equations below:
P=mv
Ek=1/2mv^2
2) A linear air track can be used to investigate collisions. Two trolleys or “gliders” are supported on a cushion of air. A glider of mass 0.30kg is stationary in the middle of the track. A second glider of mass 0.25kg and velocity of 0.20ms-1 collides with the first glider and they stick together.
You may assume that this collision is perfectly elastic.
A) What is meant by a “perfectly elastic” collision?
B) Calculate the velocity of the glider combination immediately after the collision.

6 marks


please help with B

its 0.25 x 0.2+ 0.3 x 0 = (0.25+0.3)V as one of the trolley is 0.3kg so am i right?

bef=0.05
aft=0.55v
so 0.05=0.55v
0.05/0.55= 0.0909..

am i right

Answer 1

If they stick together the collision is NOT perfectly elastic. Energy is lost as heat.

You did the velocity stuck together correctly.

If it were perfectly elastic then it is a whole different ball game.

momentum before = momentum after
0.05 = .25 V2 + .3 V1
enerrgy before = energy after
(1/2)(.25)(.2^2) = (1/2).25 V2^2 + (1/2).3 V1^2

Answer 2

so it is elastic collision, the momentum before and after is same and i dont think you need tow ok out energy