Say we consider a simple experiment of balancing a wooden rod on two fingers. The finger on the left, (1), will remain stationary, whereas the finger on the right, (2), will be moved toward the left.

Now I get to do something with that force scale I built. I had a request some time ago to talk about friction. Friction is surprisingly complicated. When two surfaces rub against each other, why is ...

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 ...

A suspended apparatus used to minimize friction during the experiment. The heavier brass cylinder and lighter ping-pong ball collide repeatedly against the transparent wall, reproducing 31 collisions ...