d. When a parachuter lands, they always bend their knees and even roll if necessary. Why do they do that?

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

When an object is heated it contracts. a. true b. false

A250-n box is at rest on a frictionless horizotal floor. then a person shoves the box with a non-zero force of magnitude p. which statement best describes the relationship betweeen p and the motion of the box after it was shoved? -the box will not move when p< 250n but otherwise will accelerate at a constant rate that is directly proportional to p - the box will begin moving at a speed that is directly proportional to p, then will gradually slow to a halt -the box will move with constant velocity at a speed that is directly proportional to p -box will accelerate across the floor at a constant rate that is directly proportional to p