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Mistake Master · AP Physics C · Unit 6 · Topic 6.1 · Step-Through Animation

Rotational Kinetic Energy: The Twin of ½mv²

You'll learnhow a spinning body stores kinetic energy even though its center never moves.

A flywheel bolted to an axle never travels an inch — and it can still power a bus. Meet kinetic energy’s rotational twin, K = ½Iω²: swap the moment of inertia I for mass and the angular speed ω for speed, keep the ½ and the square, and pick the right I for the shape.

8 STEPS · 6 QUICK CHECKS · v2

SPIN LAB
Before you start
What you're looking at
A massive flywheel bolted to a fixed axle, spinning in place, beside a two-bar energy chart.
The question
How much energy does a spin store when the center of mass never moves?
Watch for
The K_rot bar and its question mark — the flywheel travels nowhere yet clearly holds energy.
What the symbols mean
A curved arrow marks angular speed ω; the solid blue bar is K_trans, the hatched bar K_rot (joules).
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