Walking the spool

Back to 1K - Applications of Newton's Law
PIRA index: 1K10.30

Description

A big spool with a strap wrapped around its relatively small hub. Pulling the strap at different angle relative to the floor will either make the spool roll forward or backward.

Equipment

• Large spool

Instructions

Put the spool on the floor or on a table so that it can roll freely over at least a meter. Pull the strap parallel to the surface and the spool should move toward the person. Pull the strap upward and the spool will go in the other direction. Try different angles. Find the angle where the tension in the strap doesn't cause any movement of the spool.

Keywords

spool, torque