Disk Rolls Up a Ramp

This disk has a mass hidden inside of it. When started in the correct position on a ramp, the disk appears to move up the ramp as this hidden mass moves downward.

Setup:

Set the ramp on the lab table with the disk next to it.

Place the wooden disk at the bottom of the ramp with the screw for the hidden mass inside at the 1:30 position (if there was a clock on the face of the disk; see the first photo). Release the disk and it will roll up the ramp.

Notes:

This demo may require a little practice.

Courses Used In:

• PHY 10111

• PHY 10310

• PHY 10410

• PHY 30210

Discussion and Polling Questions:

• Will increasing the mass of the disk cause the demo to fail or work better? What about the hidden mass?

• How would a steeper hill change the results? Will it fail to roll uphill (assuming static friction remains)?

Equipment Needed:

• Weighted Wooden Disk

• Short Ramp