Question: prove that 1 kwh is equal to 3.6 x10 ^6 j?
Answer: Because there are 3,600 seconds to an hour; and 1 joule is the energy expended by 1 watt per second, so we have 1000 watts expended for 3,600 seconds is 1000 x 3,600 = 3.6 mega joules. Use the factor_label method.