CK-12 Physical Science Concepts - For Middle School

4.13. Types of Friction http://www.ck12.org

http://www.fearofphysics.com/Friction/friction.html

1. When do rolling and sliding friction occur in the simulations?


2. How does the surface affect the distance it takes for vehicle to stop?


3. What role does speed of the vehicle play in stopping time?


4. How is the amount of time spent sliding controlled in the simulations? How does it affect the ability of the
   vehicle to stop?

Review

1. List four types of friction.


2. You can move heavy boxes by sliding them over the ground. Or you can put them on a dolly, like the one in
   theFigure4.27, and then roll them over the ground. Explain which way makes it easier to move the boxes.

3.

FIGURE 4.27

4. What is a fluid? Give an original example of fluid friction.