1. Bell Work: Friction Details
To increase friction, ( increase / decrease ) an objects weight.
To increase friction, make the surface ( rougher / smoother ).
______ forces cause acceleration.
If the net force is zero, you are moving at a ( constant / changing ) speed.
What are the units for friction?

2. Coefficient of Friction
Tells how strong the friction force is
Depends on two things:
Weight of object
Surface conditions (rough or smooth)
Ratio of friction to normal force
Symbol: μ (mu)
Has no units

3. Static Friction Friction when an object is stationary
Higher than kinetic because you have to accelerate to overcome it.
Acceleration requires a net force.

4. Kinetic Friction Friction when an object is moving
Lower than static friction because you do not need to accelerate.
No acceleration means no net force.