The weight of an object is the gravitational force with which the earth attracts it. Newton's first law of motion states that, if no net force acts on it, every object continues in its state of rest or uniform motion in a straight line. Newton's third law of motion states that when one object exerts a force on a second object, the second object exerts an equal but opposite force on the first. Thus for every action force there is an equal but opposite reaction force . The centripetal force on an object moving along a curved path is the inward force needed to cause this motion.
Centripetal force acts toward the center curvature of the path.
Newton's law of gravity states that every object in the universe attracts every other object with a force directly proportional to both their masses and inversely proportional to the square of the distance separating them. The McGraw-Hill Companies. Any use is subject to the Terms of Use and Privacy Policy .