Multiple forces act on an object at the same time. The size and direction of these forces determines the movement of the object. Show the forces acting on an object in a free body diagram. The arrows ...

Do you need some practice with force diagrams for your introductory (or advanced) physics course? Here are three questions (and the last one is awesome) about the motion of a bike as it is pulled.

**Pre-reqs:** None. I intend to talk about forces and force diagrams, but there is a more fundamental question to address first. What is a force? Most texts define it as a push or a pull. That really ...