Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Friction is a force that exists when two surfaces rub up against each other. For example, this cup on ...

Smooth wooden surface, such as a table or floor (If you do not have a wooden surface, you can use any other type of smooth countertop or table.) Rough carpeted surface (If you do not have access to ...