Sounds like "Home Alone" . . .
Carlo is perched precariously on top of a 10-foot ladder leaning
against the back wall of an apartment building (spying on an enemy of his)
when it starts to slide down the wall at a rate of 4 ft per minute.
Carlo's accomplice, Alex, is standing on the ground 6 ft away from the wall.
How fast is the base of the ladder moving when it hits Alex?
y | \ 10
* - - - * - - *
We are given: . ft/min.
We know that: .
Differentiate with respect to time: .
So we have: .
The base of the ladder hits Alex at ft/min.