This is not dv/dt, this is dv/dh as you differentiated V with respect to h.
And you needn't apply the product rule here...
Then use the chain rule:
And solve for dh/dt at h = 6
Gravel is being dumped from a conveyor belt at a rate of 11 m^3/min The coarseness is such that it forms a pile in the shape of a cone whose base diameter and height are in the ratio of 5 to 2 . How fast is the height of the pile increasing when the pile is 6 metres high?
When I finally plug in 6 for h, I get −.0587184655608
which appears to be wrong!
What am I doing wrong here?