Friction and Normal Forces

This demonstration shows how normal force affects friction. As mass is removed from the top of the block reducing the normal force, static friction is overcome and the block begins to slide.

Setup:

Set up the equipment as shown in the image above.

Remove masses stacked on the block until the system slides. The forces can then be discussed.

Notes:

None

Courses Used In:

• PHY 10111

• PHY 10310

• PHY 10410

• PHY 30210

Discussion and Polling Questions:

• Does adding or removing mass before the block slides change the friction force on the block? How about the friction coefficient(s)?

• What would cause the coefficients of friction to change?

Equipment Needed:

• Klinger Magnetic Mechanics Kit

• String