Potential energy decreases and kinetic energy increases.
Potential energy is related to the height, since the wagon is going downhill, height decreases and potential energy decreases.
Kinetic energy is related to the speed, since the wagon is speeding up, kinetic energy increases.
Answer:
the faster an object moves the more kinetic it has. the more mass an object has, the more kinetic energy it has.
This behavior is called reflection.
Reflection is a change of in direction of the wave when it reaches another medium. Imagine a wave colliding with a glass in a tank of water.
During reflection, some of the initial energy of the wave is lost.
Waves always reflect with at same angle at which it approached the obstacle.
The study of how the world works
1) If the object changes directions with the same speed, it will be changing its velocity, because velocity is a vector, which depends on both magnitude and direction. Speed is just magnitude regardless of direction.
2) Rotational motion.