$\omega_{\text{outer}} \neq \omega_{\text{inner}}$

$\omega_{\text{outer}} = \omega_{\text{inner}}$

$\omega_{\text{avg}} = \frac{\omega_{\text{inner}} + \omega_{\text{outer}}}{2}$

$\Delta v_{\text{surface}} > 0$

Standard Differential

Locked Spool