If the acceleration of a system is zero, no external forces are acting on it. Which of the below statements is not one of Newton's Laws? 0 When a body is acted upon by a net force, the body's acceleration multiplied by its mass equal to the net force. The acceleration of a body is directly proportional to the net force applied to an object and inversely proportional to its mass, but only when the object is on the surface of the Earth 0 O A body at rest remains at rest or a body in motion remains in motion at a constant velocity unless acted on by a net external force. When one body exerts a force on a second body. the first body experiences a force that is equal in magnitude and opposite in direction to the force that it exerts. O