To demonstrate the difference in rotational inertia of the two rods, ask two students to grab the center of a wand and instruct them to rotate the wand back and forth as rapidly as they can. No matter how strong the student with the blue wand is, he or she is not able to rotate it as fast as the student with the red wand.

These two wands have the same mass and dimensions but their masses are distributed very differently giving them very different rotational inertias.

What's Included

1x Red Wand
1x Blue Wand

What to Consider

See the Buying Guide for this item's required, recommended, and additional accessories.

Description Specifications Buying Guide Documents

Product Summary

These two wands have the same mass and the same dimensions and yet the red wand is easier to rotate. This is because the red wand has two metal slugs near its center, while the blue wand has two similar metal slugs at its ends. This demonstrates that rotational inertia depends on the distribution of the mass.

These sturdy plastic wands have small holes near the center and at the ends to enable students to see where the metal is located in each wand. What initially seems a mystery can be explained to the students by allowing them to examine the wands more closely.