Block 1 is sliding toward identical block 2 on a surface of negligible friction. In situation 1, after the two blocks collide, the block 1 stops and block 2 moves off to the right. It situation 2, the two blocks collide and stick together. Which of the following claims correctly describes the motion of the center of mass of the two-block system and provides reasoning for that claim?
In situation 1, the center of mass never changes its speed, because block 1 is moving before the collision, and block 2 is moving after the collision.
Answer A: In situation 1, the center of mass never changes its speed, because block 1 is moving before the collision, and block 2 is moving after the collision.
A
In situation 1, the center of mass never changes its speed, because there are no net external forces on the system before, during, or after the collision.
Answer B: In situation 1, the center of mass never changes its speed, because there are no net external forces on the system before, during, or after the collision.,
B
In situation 2, the center of mass slows down after the collision but continues to the right, because the blocks are always moving to the right.
Answer C: In situation 2, the center of mass slows down after the collision but continues to the right, because the blocks are always moving to the right.
C
In situation 2, the center of mass slows down after the collision but continues to the right, because the direction of motion of the center of mass never changes direction in a collision.
Answer D: In situation 2, the center of mass slows down after the collision but continues to the right, because the direction of motion of the center of mass never changes direction in a collision.
D
In situation 2, the center of mass has a zero velocity, because the velocity of the center of mass of the system is always zero.