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?
3 answers
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.
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.
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.
1 answer