Answer Happy

Consider two carts moving along a track. Cart 1 is moving much more quickly than cart 2. (Both carts 1 and 2 have some clay attached to their ends so they will stick together when they collide.) Cart 1 catches up to cart 2 and collides with it. They stick together and the two carts move to the right at a speed in-between the initial speeds of carts 1 and 2. Which of the following is the complete evidence that the two carts were involved in a contact push/pull interaction? Select one: a. The two carts touched each other and they changed their speed as a result of the collision b. The two carts touched each other. c. The two carts pulled and pushed against each other. d. Cart 1 slowed down and cart 2 sped up.