A force is a push or a pull. For example, when you push open a door you must apply a force to the door. You also must apply a force to pull open a drawer. You cannot see a force but often you can see ...

From the early tribological studies of Leonardo da Vinci to Amontons’ law, friction has been shown to increase with increasing normal load. This trend continues to hold at the nanoscale, where ...

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.

Friction is immensely important to us – without it, for example, we could not walk or even crawl – yet it is only 50 years since a special word – 'tribology' – was first coined to describe its study.