Consumers pay for electricity by the kilowatt-hour (the amount of electricity used by a 1,000-watt appliance in one hour). If electricity costs 10cents per kilowatt-hour, what is the cost of running a 100-watt lamp for

1. 1 hour?
2. 24 hours?
3. 1 year?

100 watt lamp running for 1 hour uses

100/1000 kilowatts for 1 hour, so it will cost
(100/1000)*1 hour *10 cents
= 1 cent.

I'll leave #2 and #3 to you.

2. $0.24

3. $87.60

Correct!

To calculate the cost of running a 100-watt lamp, we need to determine the amount of electricity used in kilowatt-hours, and then multiply it by the cost per kilowatt-hour.

1. To find the amount of electricity used in 1 hour, we need to convert the lamp's power from watts to kilowatts. Since there are 1,000 watts in a kilowatt, the lamp's power is 100 watts / 1000 watts = 0.1 kilowatts. Therefore, the lamp uses 0.1 kilowatt-hour of electricity in 1 hour.

To calculate the cost, we multiply the electricity used (0.1 kilowatt-hour) by the cost per kilowatt-hour (10 cents).

Cost of running a 100-watt lamp for 1 hour = 0.1 kilowatt-hour * $0.10 = $0.01 (or 1 cent).

2. To find the amount of electricity used in 24 hours, we multiply the lamp's power (0.1 kilowatts) by the number of hours (24 hours). The result is 0.1 kilowatt * 24 hours = 2.4 kilowatt-hours.

To calculate the cost, we multiply the electricity used (2.4 kilowatt-hours) by the cost per kilowatt-hour (10 cents).

Cost of running a 100-watt lamp for 24 hours = 2.4 kilowatt-hours * $0.10 = $0.24 (or 24 cents).

3. To find the amount of electricity used in 1 year (assuming 365 days), we multiply the lamp's power (0.1 kilowatts) by the number of hours in a year (24 hours * 365 days). The result is 0.1 kilowatt * (24 * 365) = 876 kilowatt-hours.

To calculate the cost, we multiply the electricity used (876 kilowatt-hours) by the cost per kilowatt-hour (10 cents).

Cost of running a 100-watt lamp for 1 year = 876 kilowatt-hours * $0.10 = $87.60.