College

What is the cost of heating a tank of water with a 3000 W immersion heater for 80 minutes if electricity costs $0.10 per kWh?

Answer :

To calculate the cost of heating a tank of water with a 3000 W immersion heater for 80 minutes when electricity costs KO.10 per kWh, follow these steps:

1. Convert the Power to Kilowatts:
- The immersion heater's power is given in watts. Convert this to kilowatts by dividing by 1000.
- Power = 3000 watts = 3000 / 1000 = 3.0 kW

2. Convert Time to Hours:
- To determine the energy used, you need the time in hours. Since the time given is 80 minutes, convert this to hours.
- Time = 80 minutes = 80 / 60 = 1.333... hours (approximately 1.33 hours for simplicity).

3. Calculate Energy Used:
- Energy usage in kilowatt-hours (kWh) is calculated by multiplying the power in kilowatts by the time in hours.
- Energy = Power (in kW) x Time (in hours) = 3.0 kW x 1.333 hours = 4.0 kWh

4. Calculate the Cost of Heating:
- Finally, calculate the total cost by multiplying the energy used by the cost per kilowatt-hour.
- Cost = Energy (in kWh) x Cost per kWh = 4.0 kWh x KO.10/kWh = KO.40

So, the cost of heating the tank of water is KO.40.