I learned to respect friction, as a phenomenon with many nuances, when I was a graduate student. One day, while teaching a problem session in elementary mechanics, I unwisely invented a new problem to ...

Humans have been making fire using friction for thousands of years, with evidence of its use found in archaeological records across different cultures worldwide. Fire by friction is a testament to ...

Friction is an intrinsic physical phenomenon to curling. Without it, objects in motion would move endlessly, without slowing down. This would cause many safety-related problems: Cars or trains could ...

Consider the block shown above supported by feet at A and B that is at rest on a rough floor. A horizontal force P is applied to the right on the block. As the magnitude of P is increased slowly, two ...