Question

Before going to bed for the night, you realize that you accidentally left the kitchen lights on all day (12 hours). The lighting fixtures in the kitchen have a total of 4 incandescent bulbs, each of which uses 75 watts/hour. How much energy (in watt-hours) did you waste by leaving the lights on for the entire day?

A) 3,600 watt-hours
B) 4,500 watt-hours
C) 5,400 watt-hours
D) 6,300 watt-hours

Answer 1

Correct answer is A) 3,600 watt-hours.

To find out how much energy was wasted, multiply the power usage of each 75-watt bulb by 12 hours, resulting in 900 watt-hours per bulb, and then multiply by 4 bulbs, totaling 3,600 watt-hours (Option A).

Step-by-step explanation:

In order to calculate how much energy in watt-hours was wasted by leaving the kitchen lights on for 12 hours, we need to multiply the power usage of each bulb by the number of hours they were left on and then sum up the energy usage of all the bulbs.

Here's the calculation:

• Energy per bulb = Power rating of bulb (in watts) × Time (in hours)
• Energy per bulb = 75 watts × 12 hours = 900 watt-hours per bulb
• Total energy for all bulbs = Energy per bulb × Number of bulbs
• Total energy for all bulbs = 900 watt-hours per bulb × 4 bulbs = 3,600 watt-hours

Therefore, the correct answer is A) 3,600 watt-hours.