A microwave oven has a power requirement of 1235 W. A frozen dinner requires 6.0 min to heat on full power.
(a) How much electrical energy (in kWh) is used?
1 kWh
(b) If the cost of electricity is 12 cents per kWh, how much does it cost to heat the dinner?
2¢
what is kwh
if the cost of electricity is 12 cent per kwh,hom much does it cost to heat the dinner
6 / 60 = 0.1 hour
1235 watts = 1.235 kw
so
1.235 * 0.1 = .1235 kw hr
.1235 kw hr * .12 dollars/ (kw hr) = $0.01482
or about a penny and a half
so will the cost be 0.01cents
To answer this question, we need to understand what kWh stands for and how to calculate it.
(kWh) stands for kilowatt-hour, which is a unit of energy. It represents the amount of energy used by an electrical device rated at 1,000 watts continuously over the course of one hour.
To calculate the electrical energy used in this case, we can use the formula:
Energy (in kWh) = Power (in kW) x Time (in hours)
Now, let's calculate the electrical energy used in heating the dinner:
(a) Power requirement of the microwave oven is given as 1235 W, which is equivalent to 1.235 kW. The heating time is given as 6.0 minutes, which we need to convert to hours. There are 60 minutes in an hour, so 6.0 minutes is equal to 6.0/60 = 0.1 hours.
Using the formula, we can calculate the electrical energy used:
Energy (in kWh) = 1.235 kW x 0.1 hours = 0.1235 kWh
Therefore, the electrical energy used to heat the dinner is 0.1235 kWh.
(b) Now, to calculate the cost of heating the dinner, we need to multiply the energy used (0.1235 kWh) by the cost of electricity per kWh.
The cost of electricity is given as 12 cents per kWh, which is equivalent to 0.12 dollars per kWh.
Cost = Energy x Cost per kWh
Cost = 0.1235 kWh x $0.12/kWh = $0.01482
Therefore, it costs approximately 1.5 cents to heat the dinner.