1. F(x) = (34-.0612p)p^(-0.658) Find F'(x)

I want to apply the chain rule but I can't see how to form F(x) because of those two p's.

2. It takes a stone 3 seconds to hit the ground when dropped from the top of a building. How high is the building and what is the stone's velocity upon impact?

Am I dense? Can you solve this problem given only this?