Save guides, add subjects and pick up where you left off with your BBC account. Multiple forces act on an object at the same time. The size and direction of these forces determines the movement of ...

What, then, happens to a body when an external force is applied to it? That situation is described by Newton's Second Law of Motion. Newton's second law says that when a constant force acts on a ...

If gravity is a quantum mechanical force, adjacent free-falling masses, each of which is in a superposition of being in two places at once, could get entangled by gravity such that measuring the ...