**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 ...

Friction is a force that always opposes motion. Force is measured in newtons (N). A force is a push or a pull. Contact forces arise between two objects which are in contact. Non-contact forces act ...

Isaac Newton's First Law of Motion states, "A body at rest will remain at rest, and a body in motion will remain in motion unless it is acted upon by an external force." What, then, happens to a body ...

At the end of the 18th century, the British scientist Henry Cavendish measured the force of gravity between two objects for the first time in a laboratory. The objects in question were lead balls, one ...