Force of Friction

Overview

Link to Experience: https://play.phenomena.app/player/J5HGtNZ6qbGvQ3PKqxOD

Topics: physics, forces, friction, motion, net force, normal force, mu

Grades: 8-12

Standards: NGSS MS-PS2-2

Duration to complete: 10-15 minutes

Learning outcome: Students will learn how to calculate friction using normal force and the friction coefficient mu, and how to factor it into net force calculations — in which it always opposes other forces.

In the Classroom

Pre-Experience (Things to Look Out For):

• Do you know what friction is? Define it in your own words.

• How do you calculate normal force?

• Would an ice rink have high or low friction? What about a beach?

Post-Experience (Things to Think About):

• How does the coefficient of friction affect the friction force?

• Does an object's surface area affect the friction force? Why or why not?

• Why is the force of friction always equal to the pull force at its maximum? (Think about net force and motion)

• If an object is gliding on a frictionless surface, would it ever stop on its own?

• How do you think the force of friction would differ on another planet? (Think about the effect of gravity on the normal force!)