Question

A 100-watt bulb that burns continuously for two minutes uses 0.003 kilowatt-hour of electricity, and an 800-watt toaster uses 0.026 kilowatt-hour for a piece of toast. Which uses the greater number of kilowatt-hours?

a. The bulb

b. The toaster

c. Both use the same amount

d. Cannot be determined

Answer 1

Comparing the energy consumption of a 100-watt bulb and an 800-watt toaster, the toaster uses more kilowatt-hours at 0.026 kWh compared to the bulb's 0.003 kWh. (option b is the correct answer)

Step-by-step explanation:

When looking at which device uses more kilowatt-hours (kWh), we need to compare the energy consumption of both devices. A 100-watt bulb that burns continuously for two minutes uses 0.003 kilowatt-hours of electricity. In contrast, an 800-watt toaster uses 0.026 kilowatt-hours to toast a piece of bread.

By comparing these two amounts, we can see that the toaster uses a greater number of kilowatt-hours than the bulb. Therefore, the answer to the question is (b) The toaster.

The energy used by a device is calculated using the relationship E = Pt, where E is the energy in kilowatt-hours, P is the power in kilowatts, and t is the time in hours that the device is used.

The toaster uses a greater number of kilowatt-hours than the bulb, as indicated by the calculated energy consumption values. This difference arises from the higher wattage of the toaster, emphasizing the importance of both power and duration in determining energy usage.