1. An object initially at rest falls from a height H until it reaches the ground. Two of the following energy bar
charts represent the kinetic energy K and gravitational potential energy Us of the object-Earth system at
two positions. The first position is when the object is initially released, and the second position is when the
object is halfway between its release point and the ground. Which two charts could represent the mechanical
energy of the object-Earth system? Select two answers.