(Solved): A different group is worried that the motion detector will not effectively track the falling object, ...

A different group is worried that the motion detector will not effectively track the falling object, so they decifle to roll a round object down a ramp instead of dropping it. They measure the initial height to calculate gravitational potential energy, use the motion detector to track the final velocity, and calculate the kinetic energy of the object at the end. Despite all their careful measurements, it appears that energy is not conserved! The object is not moving as fast at the bottom as the initial gravitational potential would have led them to predict. Which of the following suggestions is possible? Select all that apply.