Block 1 is moving toward block 2 with a speed v on a one-dimensional frictionles
ID: 1770204 • Letter: B
Question
Block 1 is moving toward block 2 with a speed v on a one-dimensional frictionless surface. Block 1 has a mass m, while block 2 has a mass nm, where n is a positive integer. Which of the following statements is true if the final speeds of the blocks are the same immediately after the collision (assume there is just one)?
A. Since n cannot be zero, energy cannot be conserved in the collision. However, momentum is still conserved.
B. Energy is not conserved because the masses are identical. Momentum is conserved, however.
C. Energy is conserved, which implies that the masses are identical and n = 1. Momentum is conserved as well.
D. Energy is not conserved, but neither is momentum because the blocks exert forces on one another during the collision.
E. Energy and momentum are not conserved because the masses move together after the collision.
F. Momentum is not conserved because conservation of momentum implies that n = 1, meaning that the masses are identical. Energy is also not conserved.
Explanation / Answer
B. Energy is not conserved because the masses are identical. Momentum is conserved, however.
The situation might yield the same velocity after collision, So this seems more appropriate.