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?

.12 * 5.0 * 20.0 * 220 / 1000

A * V = watts

watts * 5 = watt·hr

dividing by 1000 gives kw·hr

To calculate the cost of operating an electric oven, you need to determine the total energy consumed by the oven during the given time period, and then multiply that by the cost of electrical energy.

First, let's find the power consumed by the oven using the formula:
Power (P) = Current (I) × Voltage (V)

Given:
Current (I) = 20.0 A
Voltage (V) = 220 V

Substituting the values into the formula, we have:
Power (P) = 20.0 A × 220 V
Power (P) = 4400 W (watts)

Next, we need to calculate the energy consumed by the oven. Energy (E) can be calculated using the formula:
Energy (E) = Power (P) × Time (t)

Given:
Time (t) = 5.0 h

Substituting the values into the formula, we have:
Energy (E) = 4400 W × 5.0 h
Energy (E) = 22,000 Wh (watt-hours)

Finally, to convert watt-hours (Wh) to kilowatt-hours (kWh), divide the energy value by 1000:
Energy (E) = 22,000 Wh ÷ 1000
Energy (E) = 22 kWh

Now we can calculate the cost of operating the electric oven. Since the cost of electrical energy is $0.12 per kilowatt-hour, we can multiply the energy value (in kilowatt-hours) by the cost:
Cost = Energy (E) × Cost of energy per kilowatt-hour

Given:
Cost of energy per kilowatt-hour = $0.12

Substituting the values into the formula, we have:
Cost = 22 kWh × $0.12/kWh
Cost = $2.64

Therefore, it would cost $2.64 to operate the electric oven for 5.0 hours at a current of 20.0 A and a voltage of 220 V, assuming the cost of electrical energy is $0.12 per kilowatt-hour.