The gravitational force and potential energy at the surface of a planet with radius $r$ are $f_1$ and $u_1$, respectively. what are the gravitational force and gravitational potential energy, $f_2$ and $u_2$, respectively, at the surface of a planet with radius $2r$ that has the same mass density?

Which of the following represents an upright image? a. -do b. +m c. -m d. +do

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

What is the weight of a feather (mass = 0.0001 kg) that floats through earth's and the moon's atmospheres?