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 ...

The problem really is to identify the dominant dissipative mechanism, for a given disk and a given surface, and then to evaluate the associated rate of dissipation of energy as a function of the angle ...

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 ...