Respuesta :
Answer:
(a) 142.37 kWh (b) 1708.44 cents
Explanation:
It is given that the microwave has a power requirement of 1238 W
The frozen dinner takes 6.9 minutes to heat
So time t =6.9 minutes [tex]=\frac{6.9}{60}=0.115hour[/tex]
(a) The total energy used = power ×time = 1238×0.115=142.37 kWh
(B) The cost of the electricity is 12 cents per kWh
So total cost = 12×142.37=1708.44 cents
Answer:
a) 0.14237 kWh
b) 1.70844 cents
Explanation:
Electrical energy is defined as amount of work done per unit time.
or
The product of power and time is energy
a) Power of the microwave is 1238 W
Time the microwave is operating is 6.9 minutes
Converting to hours
6.9/60 = 0.115 hours
Power
P = 1238 × 0.115
⇒P = 142.37 Wh = 0.14237 kWh
∴ Electrical energy used is 0.14237 kWh
a) 1 kWh requires 12 cents
Cost required to use microwave
0.14237×12 = 1.70844 cents
∴ Cost to heat the dinner is 1.70844 cents
