1.1 What is friction? Take this everyday example: when a coffee mug rests on a flat table, the kinetic frictional force is zero. There is no force trying to move the mug across the table, so there is ...

This acts when an object is at rest and prevents it from starting to move. It increases up to a certain limit as you apply an external force to initiate motion. This acts when an object is already in ...

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 ...