A 100W light bulb is left on for 10hrs. Over this period of time how much energy is used by the bulb?

am i doing this right?

my guess is to convert 100W to kW
and convert 10 hrs to seconds and multiply the 2 together?
which gives 3600J or should i just leave it in watts?

A 100W light bulb is left on for 10hrs. Over this period of time how much energy is used by the bulb?

am i doing this right?

my guess is to convert 100W to kW
and convert 10 hrs to seconds and multiply the 2 together?
which gives 3600J or should i just leave it in watts?

If you want the answer in Joules (watt-seconds), multiply 100 W by 36,000 seconds.

If you want the answer in kilowatt-hours, multiply 0.1 kw by 10 hours. That's just 1.0 kwh. That would cost you about 15 to 20 cents from most utility companies these days.

So we know that 1 Watt is equal to 1 Joule per second. So 100 Watts is equal to 100 joules per second.

This means we first need to convert 10 hours to seconds.
(10 Hours) * (60) = 600 Minutes * 60 = 36000 seconds.

Now we know that Power = Work/Time.

Since we're solving for Work, we multiply by T to get Power * Time = Work.

Now we just plug in:
(100 Joules per second) * (36000 seconds) = 3,600,000 Joules of work.

To calculate the energy used by the light bulb over a period of time, you need to consider the power (wattage) of the bulb and the duration it is left on. Here are the correct steps to calculate the energy used:

1. Convert the power of the bulb from watts (W) to kilowatts (kW). Since 1 kilowatt is equal to 1000 watts, divide the power in watts by 1000. In this case, 100W ÷ 1000 = 0.1 kW.

2. Keep the time in hours. In this case, it's already given as 10 hours.

3. Multiply the power (in kW) by the time (in hours) to get the energy used. In this case, 0.1 kW × 10 hours = 1 kilowatt-hour (kWh).

So, the light bulb will use 1 kilowatt-hour of energy over the 10-hour period. It's common to express energy consumption in kilowatt-hours rather than watts, as it provides a more practical measure for understanding utility bills and energy consumption.

Therefore, your calculation is incorrect. The energy used is 1 kilowatt-hour (kWh), not 3600 joules (J) or watts (W).