We might naively expect rough surfaces to show greater friction, for example, yet it is sometimes ... As with many mysteries of physics, this one seems to have quantum origins, with close links ...

Students could try to recreate this fun 'friction book' activity in class, possibly as a strength test between groups of students. They could also give additional examples of uses in friction in ...

Friction is a force that opposes motion. It is present whenever two surfaces rub over each other, such as when you rub your hands together, or when you apply the brakes on a bike or in a car.