Friction

Question 1

What is friction?

Answer 1

A force that arises when two surfaces are in contact with each other

Question 2

Friction depends on:

Answer 2

Surface roughness, material properties, adhesion, deformation, temperature, fluid films, velocity effects, etc.

Question 3

Dry friction is separated into ____ and ____.

Answer 3

Static Friction and Dynamic Friction

Question 4

Which arrow represents the tangential direction?

Answer 4

Horizontal arrow

Question 5

The more normal force you have, the less available frictional force you have (T/F)

Answer 5

False

Question 6

What is static friction equal and oppose?

Answer 6

Net forces in tangential direction until movement starts

Question 7

A book has a weight of 10 N and a coefficient of friction equal to 0.10 between the book and table. What is the force of friction acting on the book?

Answer 7

F(friction)= coe(friction) F(normal)
Fy=may –> 0
Fn - Fg= 0
Fn= Fg= 10N

Question 8

Dynamic friction does not remain constant regardless of the velocity of a surface in motion (T/F)

Answer 8

False

Question 9

Calculate the dynamic friction force acting on the sled. Note that the sled is not moving at a constant velocity

Answer 9

Step 1: Create a free-body diagram and identify forces
Step 2: Decompose the pull force into its X and Y components
Step 3: Calculate normal force
Step 4: Calculate dynamic friction force
Answer: -27.42 N

Question 10

Static friction is more likely to have a larger value than dynamic friction (T/F)

Answer 10

True