How to solve this problem?

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1 Answer
Oct 27, 2017

2,439 kw (rounded)

Explanation:

"varies directly as the cube of the wind speed S" means that
#P = cS^3#, where c is some constant you don't know, yet.

But you can derive it, since you are told that when S = 27, P = 750

#750 = c(27^3) = c(19,683)#
...therefore #c = 750/19683# = .0381 (rounded)
...so then you can plug in 40:

#P = .0381(40^3) = .0381(64000) = 2,439 kw# (rounded)

GOOD LUCK