1. Checking for Understanding: Friction
On page ____ of your notebook, label the page with the title above.
Number from 1 to 10.

2. The cause of forces
A ___#1___ is a push or pull, or any action that has the ability to change motion.
The key word here is action, force is an action.

3. 13.1 Friction
Friction is a force that resists the ____#2___ of objects or surfaces.
Many kinds of friction exist.

5. 13.1 Friction Friction depends on both of the surfaces in contact.
When the hockey puck slides on ice, a thin layer of water between the rubber and the ice allows the puck to slide easily.

6. 13.1 Identifying friction forces
Friction is a force, measured in __#3___ just like any other force.
____#4___ friction keeps an object at rest from moving.

7. 13.1 Identifying friction forces
____#5___ friction is a force that resists the motion of an object moving across a surface.

8. 13.1 A model for friction
The greater the force squeezing two surfaces together, the ___#6____ the friction force.

9. 13.1 Reducing the force of friction
Unless a force is constantly applied, friction will slow all motion to a __#7__ eventually.
It is impossible to completely get rid of friction, but it can be reduced.

10. 13.1 Reducing the force of friction
#8: identify one way that we reduce the force of friction

11. 13.1 Useful friction #9: do these tires increase or decrease friction?
Friction is also important to anyone driving a car.
Grooved tire treads allow space for water to be channeled away from the road-tire contact point, allowing for more friction in wet conditions.
#9: do these tires increase or decrease friction?

12. #10: Which type of friction is stronger?
Sliding friction
Rolling friction
Rolling

13. Answers: Force Greater Motion Stop Newtons Lubricant Static Increase
Sliding