Question

With a 1200-W toaster, how much electrical energy is needed to make a slice of toast (cooking time = 1 minute)?

a. 0.20 kWh
b. 0.02 kWh
c. 1.20 kWh
d. 0.60 kWh

Answer 1

The electrical energy needed to make a slice of toast with a 1200-W toaster in 1 minute is 0.02 kWh, and the cost of making the toast, based on the electricity rate, is $0.0018.

Step-by-step explanation:

The amount of electrical energy needed to make a slice of toast with a 1200-W toaster in 1 minute can be calculated by using the formula for electrical energy consumption E = Power × Time.

Since power is given in watts and time in minutes, we first convert the time to hours because energy consumed is typically expressed in kilowatt-hours (kWh).

1 minute is equal to 1/60 hours.

Thus, the energy consumed (E) in kWh is E = (1200 W × (1/60) hours) / 1000 = 0.02 kWh.

At the rate of 9.0 cents per kWh, the cost to make a slice of toast is therefore 0.02 kWh × $0.09/kWh = $0.0018, which is less than a cent.