Friction and Force Flashcards
1
Q
Define “Friction”
A
Friction is a force that opposes motion and occurs when two surfaces are in contact
2
Q
What affects friction?
A
Friction depends on:
- how rough the surfaces in contact are
- how hard the surfaces are pushed together
3
Q
When is friction good?
A
- brakes in a vehicle
- friction between our feet and the ground
- when walking, sitting on a chair, driving
4
Q
When is friction bad?
A
- pushing a heavy object, friction makes it harder to move
- producing heat (e.g. a car engine)
5
Q
How do you reduce and increase friction?
A
Reduce friction: smooth surfaces, lighter pressure against two surfaces, lube objects (e.g. oil in a car)
Increase friction: rough surfaces, harder pressure against two surfaces
6
Q
How do you measure force?
A
Force-meters
7
Q
Convert kg to N:
- 1kg
- 5kgs
- 20kgs
A
- 10N
- 50N
- 200N
8
Q
How can force be presented on a diagram?
A
- arrows are used to show the direction of forces
- the strength of a force is shown by the thickness or length of an arrow
