physics
posted by Justin .
(a) A solar collector is 12.0% efficient in gathering solar energy and converting it to heat. If the average intensity of sunlight on one day is 700 W/m2, what area(m^2) should your collector have to gather energy at the rate of 150 W?
(b) What is the maximum cost ($)of the solar panel if it must pay for itself in two years of operation averaging 9.00 hours per day? Assume that it earns money at the rate of 3.00¢ per kilowatthour. There are 365.25 days in a year.

(a)
0.12•I•A = P,
A=P/0.12•I = 150/0.12•700 = 1.79 m².
(b)
2•365.25•(9•0.150)kW•h• 3 ¢/kW•h =
=2958.5 ¢