Asmall gasoline engine can put out 24,000 n-m/min of mechanical power. the engine is used to drive an electrical generator that is 70 percent efficient. 1 n-m = 2.78 x 10-4 w-h. find the output of the generator in watts.

Actually, Newton-meter or N-m is equivalent to Joules. On the otherhand, watts in simplified units, is Joules/second. So, first, convert J/min to J/s.

24,000 J/min (1 min/60 s) = 400 J/s = 400 W

Since the efficiency is 70%, then the output is:

Output = (400)(0.7) = 280 Watts