Difficulty: Hard

Average Score: 0%

Different types of light bulbs use different amounts of electricity. Electricity use is measured in kilowatt hours (kWh). The electricity use per hour (kWh) of an electrical device can be calculated using the following equation:

A 60W light bulb used .48 kilowatt hours of electricity. How long was the light bulb on?

Rationale

The light bulb was on for 8 hours.

To find out how long the light bulb was on, we can use the formula for energy consumption which states that energy (in kilowatt hours) equals power (in kilowatts) multiplied by time (in hours). A 60W light bulb is equivalent to 0.06 kilowatts. Therefore, to consume 0.48 kilowatt hours, the light bulb must have been on for 8 hours.

A (0.48 hours) YOUR ANSWER

This choice suggests that the light bulb was only on for a fraction of an hour, approximately 29 minutes. However, using the formula, we find that 0.06 kW multiplied by 0.48 hours equals only 0.0288 kWh, which does not match the given energy consumption of 0.48 kWh.

B (28.8 hours) YOUR ANSWER

While this choice indicates a longer duration, it vastly overestimates the time the light bulb was on. If the light bulb were on for 28.8 hours, it would consume 0.06 kW * 28.8 hours = 1.728 kWh, far exceeding the stated 0.48 kWh.

C (0.125 hours) YOUR ANSWER

This option indicates that the light bulb was on for only 7.5 minutes. However, when calculating, 0.06 kW multiplied by 0.125 hours equals only 0.0075 kWh, which is significantly lower than the 0.48 kWh mentioned in the question.

D (8 hours) CORRECT

This choice correctly states that the light bulb was on for 8 hours. When using the formula, 0.06 kW multiplied by 8 hours equals 0.48 kWh, matching the energy consumption provided in the question.

Conclusion

The energy consumption of the 60W light bulb can be accurately calculated using its power rating and the time it was in use. The light bulb being on for 8 hours aligns perfectly with the energy consumption of 0.48 kilowatt hours, confirming that this is the correct duration. Other options fail to match the energy consumption or calculate to incorrect values. Thus, the conclusion affirms the light bulb was indeed on for 8 hours.

A 60W light bulb used .48 kilowatt hours of electricity. How long was the light bulb on?

The light bulb was on for 8 hours.

Related Questions

Related Quizzes

How familiar were you with this question?

Report an Issue

Rate this Practice Test