## Precalculus (10th Edition)

$2291.94\text{mph}$
The distance from the Moon to the Earth is: $r=2.39\cdot10^5$ miles. The Moon takes $27.3$ days($=27.3\cdot24$ hours) to make a revolution, hence its angular velocity is: $\omega=\frac{2\pi}{t}=\frac{2\pi}{27.3\cdot24}=9.589\cdot10^{-3}\frac{\text{rad}}{\text{hr}}.$ Therefore the linear velocity at $40^\circ$: $v=\omega r\\v=9.589\cdot10^{-3}(2.39\cdot10^5)=2291.94\text{mph}$