Question

If electrical energy costs 12 cents, or $0.12, per kilowatt-hour, how much does it cost to operate an electric over for 5.0 h if it carries a current of 20.0 A at 220 V?

Answer 1

.12 * 5.0 * 20.0 * 220 / 1000

A * V = watts

watts * 5 = watt·hr

dividing by 1000 gives kw·hr