AP Physics C: Mechanics / Unit 5: Torque and Rotational Dynamics
5.1 Rotational Kinematics
Notes
Rotation uses angular position $\theta$ (radians), angular velocity $\omega$ (rad/s) and angular acceleration $\alpha$ (rad/s²).
- Constant $\alpha$: $\omega=\omega_0+\alpha t$, $\displaystyle \theta=\omega_0t+\frac{1}{2}\alpha t^2$, $\omega^2=\omega_0^2+2\alpha\Delta\theta$.
Practice
A wheel speeds up from 0 to 12 rad/s in 4 s. $\alpha=$
$\displaystyle \frac{12}{4}$.
One full revolution is:
Full circle.
A disk spins at constant $\omega$. Its angular acceleration:
No change in $\omega$.
$\theta(t)=t^3$ rad. $\omega$ at $t=2$ s:
$\omega=3t^2$.
Ready for more? Take the Unit 5 test.