Angular acceleration follows net torque, not angular velocity

01
The tempting model
Assuming a spinning object must have a net torque because ω is nonzero.
02
Why it feels right
Motion feels like it requires a continuing cause.
03
Where it breaks · how to catch it
You infer torque from rotation speed instead of from changing rotation speed.
04
The correct model
Net torque equals Iα. Constant angular velocity means α = 0 and net torque = 0, even though ω is nonzero.
05
Repair · see it, then test it
worked example A wheel spins at constant angular speed with negligible friction. What is net torque?
Tempting move
Nonzero, to keep it spinning.
Correct move
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.
Then practise it on the ladder
R41Torque causes angular accelerationadds: Net torque changes angular velocity; it does not maintain it.