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 ...

Think about the last time you made a purchase using your phone. Maybe you were at a coffee shop and when your turn came, you opened your payment app, tapped your phone on the payment device, grabbed ...

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 ...