Collision problem (a) Two carts collide on a track and after collision, they sti
ID: 1484354 • 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
after collision carts stick together.
so final speed of both carts is same = - 5m/s (negetive sign means to the left)
momentum conservation
m*10 + m*v = - (m+m)*5
10 + v = -10
v = 20 m/s (to left)
b)
momentum conservation
m*10 + 0 = m*(-8) + m*v
v = 18 m/s (to right)
c)
in second scenario, KE of the system is conserved.
(KE conserved in elastic collision)