Angular acceleration follows net torque, not angular velocity

The mistake

Assuming a spinning object must have a net torque because ω is nonzero.

Why it feels right

Motion feels like it requires a continuing cause.

How to catch it

You infer torque from rotation speed instead of from changing rotation speed.

The first principle

Net torque equals Iα. Constant angular velocity means α = 0 and net torque = 0, even though ω is nonzero.

worked mini-example

A wheel spins at constant angular speed with negligible friction. What is net torque?

Common wrong move

Nonzero, to keep it spinning.

Correct

Zero; torque would change ω.

Test the repair ROT-08 · transfer

A disk spins counterclockwise while a braking torque acts clockwise. The angular acceleration is:

Counterclockwise because the disk rotates that way Clockwise, in the torque direction Zero until the disk stops Radially inward

Make a fresh prediction before referring to the worked example.