Two identical blocks are connected by a lightweight string that passes over a lightweight pulley that can rotate about its axle with negligible friction. The two-block system is released from rest and the blocks accelerate. Which of the following correctly relates the potential energy gained by the block 1-Earth system to the potential energy lost by the block 2-Earth system and provides correct evidence?
1) Both blocks travel the same distance
2) Both blocks gain the same amount of kinetic energy
