Probably everyone is familiar with the phenomenon: water drops cling to a pane of glass, if it is tilted out of the horizontal plane. Only when a certain angle is reached they slide off. This raises ...

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 ...