Question

How many kWh of energy does a 543 W toaster use in the morning if it is in operation for a total of 8 min?
(answer in kWh)

At a cost of 12 cents/kWh, estimate how much would this add to your monthly electric energy bill if you made toast four mornings per week. (Assume a month of 4 weeks.)
(answer in cents/month)

Answer 1

Concepts and reason

The concept used to solve this problem is the rate of energy transfer.

Use the relation between power, energy and time to calculate the required energy.

Fundamentals

The expression for power is,

Here is the power, is the energy and is the time.

Convert the energy from to.

$13=2.777778x10-kWh $

Expression for the power is,

Rearrange the equation in terms of E.

Substitute for and for .

Convert the energy from to.

$13=2.777778x10-kWh $

Since the energy in kilo watt hour is,

The total energy used by toaster in the morning is.

Consider the month is of four weeks.

You use the toast in four mornings in a week.

The total number of days used in a month is days.

Total electric energy used in one morning is .

The cost per one is .

Since the total monthly electric energy bill is,

The total energy electric bill per month is.

Ans:

The total energy used by toaster in the morning is.

The total energy electric bill per month is.