Question

Two identical blocks, A and B, are on a horizontal surface, as shown above. There is negligible friction between the surface and the blocks. As shown in Figure 1, block A is initially moving toward block B with speed vA=v0 and block B is initially at rest. Figure 2 shows the blocks in contact as they collide a short time later. In both figures, the location of the center of mass of the two-block system is indicated by the X that is labeled CM.
During the time that the blocks are in contact, describe whether the center of mass of the two-block system is speeding up, slowing down, or staying the same. ____ Speeding up ____ Slowing down ____ Staying the same Briefly describe, in terms of a basic law of physics, whether the center of mass of the two-block system is speeding up,

Answer 1

Answer:

  the speed of the center of mass stays the same

Explanation:

In a system with no energy loss, momentum is conserved if the mass remains constant. The system described has no change in mass, and energy loss is considered negligible. Hence the product of the total mass and the velocity of its center will be a constant. The center of mass stays the same speed.