Answer: The correct answers are kinetic energy and the potential energy.
Step-by-step explanation:
The kinetic energy is due to the motion of the object. The potential energy is due to the position of the object.
In the given problem, the skater's board falls back to the ramp. When the skater'board falls on the ramp then the potential energy will get decreased and the kinetic energy will get increased and vice versa when the skater's board moves up the ramp.
The total energy of the skater's board remains constant when the skater's board moves down the ramp. The total energy of the skater's board remains constant when the skater's board moves up the ramp. It follows the law of conservation of energy.
Therefore, the correct answers are kinetic energy and the potential energy.