(Solved): A street light is at the top of a 15 foot tall pole. A 6 foot tall woman walks away from the pole w ...

A street light is at the top of a 15 foot tall pole. A 6 foot tall woman walks away from the pole with a speed of $6\mathrm{ft}/\sec$ along a straight path. How fast is the tip of her shadow moving when she is 30 feet from the base of the pole? The tip of the shadow is moving at $\mathrm{ft}/\sec$.