One group approached their investigation by dropping a mass so it fell vertically downward. they planned to measure the position of the mass as it descended using a motion detector. they checked whether the motion detector that they were using was sensitive enough to capture the motion during the fall, and they were satisfied.

given that they are measuring the motion (position, velocity, and acceleration) of the mass, the students can only measure gravitational potential energy and kinetic energy; any other form of energy is undetectable. if they hope to see that energy is conserved in this system, which of the following assumptions must be true (or approximately true)?

air resistance is negligible.