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. This must be
true.
The initial vertical velocity of the mass is negligible. [Select ]