Final answer:
The bat hit by a stationary ball will absorb the ball's kinetic energy, causing slight movement or vibration. The difference during a second impact with a swinging bat lies in the added kinetic energy from the bat's motion, leading to a more effective energy transfer and a farther-traveled ball.
Step-by-step explanation:
When a bat and ball meet while the bat is held without moving, the bat will experience a force due to the ball's impact. The kinetic energy of the moving ball is transferred to the bat upon collision, causing the bat to vibrate or move slightly, depending on the mass of the bat and how firmly it is held. If the bat meets the ball a second time with the bat being swung, the bat will have its kinetic energy as well as the energy transferred from the ball. In both situations, the conservation of momentum principle applies, and kinetic energy is exchanged. However, the difference in what happens to the bat during each impact can be attributed to the varying amounts of kinetic energy present.
During the first scenario, the ball's kinetic energy is partially absorbed by the bat, and because the bat was stationary, its initial kinetic energy is zero. Some of the ball's kinetic energy will be lost due to the deformation of the ball and the sound or heat produced during the collision. When the bat is swinging, it already has kinetic energy that adds to the impact, resulting in a more effective transfer of energy to the ball, which often results in the ball traveling farther after being hit.