Author Question: Car A rear ends Car B, which has twice the mass of A, on an icy road at a speed low enough so that ... (Read 123 times)

kshipps · **on:** Jul 28, 2018

Car A rear ends Car B, which has twice the mass of A, on an icy road at a speed low enough so that the collision is essentially elastic. Car B is stopped at a light when it is struck. Car A has mass m and speed v before the collision. After the collision
a. each car has half the momentum.
b. car A stops and car B has momentum mv.
c. car A stops and car B has momentum 2mv.
d. the momentum of car B is four times as great in magnitude as that of car A.
e. each car has half of the kinetic energy.

Question 2

Two blocks with masses 2.0 kg and 3.0 kg are placed on a horizontal frictionless surface. A light spring is placed in a horizontal position between the blocks. The blocks are pushed together, compressing the spring, and then released from rest. After contact with the spring ends, the 3.0-kg mass has a speed of 2.0 m/s. How much potential energy was stored in the spring when the blocks were released?
a. 15 J
b. 3.0 J
c. 6.0 J
d. 12 J
e. 9.0 J