To estimate the amount of wood in the trunk of a tree, it is reasonable to assume that the trunk is a cutoff cone (see the figure).

If the upper radius of the trunk is r, the lower radius is R, and the height is H, the volume of the wood is given by

Suppose r, R, and H are increasing at the respective rates of 4 in /yr, 5 in/yr, and 9 in/yr. At what rate is V increasing at the time when r = 2 feet, R = 3 feet, and H = 15 feet?

Transcribed Image Text:

H R