Final answer:
Sand falling from a conveyor at a sand and gravel plant undergoes projectile motion, following a parabolic path influenced by gravity, experiences air resistance, and is in a form of free fall.
Step-by-step explanation:
The motion of sand falling off a conveyor at a sand and gravel plant can be described as projectile motion. When objects are projected into the air and influenced by gravity, they tend to follow a parabolic trajectory. This projectile motion occurs because gravity acts as a constant acceleration towards the center of the Earth, assuming that air resistance is negligible. If air resistance is considered, it opposes the motion of falling objects, acting in the direction opposite to their movement, and affects objects with larger surface areas more significantly. In free fall, objects are subject to the acceleration due to gravity, with their downward acceleration remaining constant throughout their ascent and descent. Thus, when sand falls off a conveyor, it demonstrates projectile motion, experiences air resistance, follows a parabolic trajectory, and undergoes a form of free fall while being affected by gravity.