AP Physics C: Mechanics / Unit 6: Energy and Momentum of Rotating Systems
6.2 Torque and Work
Notes
Work done by a torque: $W=\tau\Delta\theta$. Net work changes rotational KE.
Practice
A 5 N·m torque turns a wheel through 4 rad. Work:
$\tau\Delta\theta$.
That work goes into:
Work-energy theorem.
A torque opposite the rotation does:
Slows it down.
Work by a varying torque:
Integrate over the angle.
Rotational power is:
Like $P=Fv$.
Ready for more? Take the Unit 6 test.