Collision problem (a) Two carts collide on a track and after collision, they sti
ID: 1483709 • Letter: C
Question
Collision problem
(a) Two carts collide on a track and after collision, they stick together. If the initial velocity of the 1st cart =10m/s right and its final velocity is 5m/s left, what was the 2nd cart’s initial and final velocity assuming both carts have the same mass of 10kg.
(b) If instead of sticking with the 2nd cart, the 1st cart bounces back with the speed of 8m/s and we assume it’s a perfectly elastic collision, what is the other cart’s final velocity, assuming it was at rest initially?
(c) In which scenario, is the KE of the system conserved?
Explanation / Answer
(a)
v1 = 10 m/s
v = - 5 m/s
m = 10 Kg
Using Momentum Conservation-
m*v1 + m*v2 = (m+m)*v
10*10 + 10*v2 = (10+10) * (-5)
v2 = - 20 m/s
2nd cart’s initial velocity = 20 m/s towards Left.
2nd cart’s Final velocity = 5 m/s towards Left.
(b)
m= 10 kg
v1 = 10 m/s right
v2 = 0 m/s (At rest)
v1f = 8 m/s
v2f = ?
Using Momentum Conservation
10 * 10 + 10 * 0 = - 10*8 + 10 * v2f
v2f = 18 m/s
(c)
Kinetic Energy is Conserved during the Elastic Collision i.e the 2nd Part.