A model for friction: Working with friction

Question 1

Define friction

Answer 1

• when two objects are in contact, there is a force between them
• the normal reaction at 90° to the surface
• the friction force which opposes likely motion

Question 2

Describe smooth surface

Answer 2

friction is negligible

Question 3

Describe rough surface

Answer 3

means friction is working against the object

Question 4

General formula for friction

Answer 4

F <= μR

Question 5

Define limiting friction

Answer 5

is the maximum value Fmax = μR
This happens when:
- the object is moving
- the object is on the point of moving