A street light is mounted at the top of a 15ft tall pole. A man 6ft tall walks away from the pole with a speed of 5ft/sec along a straight path. How fast is the tip of his shadow moving when he is 40ft from the pole?
1 Answer
Explanation:
The street light is mounted at the top of a
Let this be depicted by the figure shown below.
Here the distance of the man from lamp post be
Then, as they form similar triangle, we have
and shadow is
and hence, shadow moves with a speed of