A 100 watts light bulb has an average life of 2000 hours. How much energy does it consume over its lifetime?
The only thing I got was power=100 watts and time = 2000 hours but I need to convert to seconds and I don't kn how to do that.
there are 60*60 = 3600 seconds/hr
2000 hr *3600 s/hr = 72*10^5 s
times 100 watts = 72*10^7 Joules
720 million Joules :)
If you want to do that, 3600sec/hr.
However, the problem did not state the units of power. If you use Kw-hr, the problem is simple:
energy=.1 kw * 2000hrs=200kw-hr
To convert the time from hours to seconds, you need to know that there are 3600 seconds in one hour.
Here's how you can calculate the energy consumed by the 100-watt light bulb over its lifetime:
1. Convert the time from hours to seconds: Since there are 3600 seconds in one hour, multiply 2000 hours by 3600 seconds/hour.
Time in seconds = 2000 hours * 3600 seconds/hour = 7,200,000 seconds.
2. Calculate the energy consumed by multiplying the power (in watts) by the time (in seconds).
Energy consumed = Power * Time = 100 watts * 7,200,000 seconds.
To find the energy consumed in watt-seconds, you multiply the power by the time. However, this unit might not be very intuitive, so let's convert it to kilowatt-hours (kWh), which is a more common unit for measuring energy consumption.
3. Convert watt-seconds to kilowatt-hours: There are 3,600,000 watt-seconds in one kilowatt-hour. Divide the energy consumed in watt-seconds by 3,600,000 to get the energy consumed in kilowatt-hours.
Energy consumed = (Power * Time) / 3,600,000.
Applying the values:
Energy consumed = (100 watts * 7,200,000 seconds) / 3,600,000 = 200 kilowatt-hours.
Therefore, the 100-watt light bulb will consume 200 kilowatt-hours of energy over its lifetime.