1. Friction

2. Friction makes it possible:
To walk
Use wheeled vehicles
Sit
Hold books

3. WHAT IS FRICTION?
A force that opposes motion
 • What does oppose mean???
 • Oppose means…goes against

4. Frictionis a
force that occurs
when 2 surfaces
oppose each
other.

5. Rub your hands
together to
produce friction.

6. Types of friction
 There are four types of friction
 Static
 Sliding
 Rolling
 Fluid

7. Static
Friction
that acts on
something that is not
moving
 Piano is held in place by static
friction
 Static friction keeps you in your
seat

8. Sliding
Force resulting when
pushing or pulling an
object over a surface.
 Moving day—pushing a box
across the floor

9. Rolling
Contact is reduced
because of rollers or
wheels or ball bearings.
 Skate boards have ball bearings in
the wheels.
 A cart has wheels.

10. Fluid friction
Resistance from a
“liquid” or air.
 Stirringa thick batter
 Walking through water
 Olimpic swimmers