The force of gravity on the surface of a planet will affect a person's or object's
a.
mass.
b.
terminal velocity.
c.
weight.
d.
free fall.

Which explanation describes the forces involved for a person to walk down the sidewalk? a. the person's feet push backward on the sidewalk; the sidewalk pushes backward on the person. b. the person's feet push forward on the sidewalk; the sidewalk does not push on the person. c. the person's feet push backward on the sidewalk; the sidewalk pushes forward on the person. d. the person's feet push forward on the sidewalk; the sidewalk pushes forward on the person.

Explain earth's motion, using the terms "precession" and "rotation" in your answer.

The energy released by a nuclear fusion reaction is produced when