friction Flashcards
1
Q
what is friction?
A
friction is the force between two surfaces leading over one another that causes them to heat up and wear
2
Q
what does friction always oppose?
A
motion
3
Q
name when friction is useful
A
grip-walking, cycling, driving, writing (tyre grip), brake-cycle, car, lighting matches, bow string contact, keep your trousers up
4
Q
name when friction is not useful
A
air resistance, friction burns, wears things away such as tyres
5
Q
how can we reduce friction?
A
lubrication(using oil, grease etc.), streamlining
