How many watt-hours are there in 1000 joules? Please explain mathematically.

1 Answer
Mar 1, 2018

0.278 watt-hours

Explanation:

Start with the basic definition:
1 Joule is energy lost as heat when an electric current of 1 ampere passes through a resistance of 1 ohm for 1 second.

Consider the power generated in the above circuit in watts: # I^2 R# ,
So that is 1 watt-second
1 hour is 3600 seconds
Or #1/3600# watt-hour
Or #2.78 * 10 ^-4# watt-hour

So 1000 joules will be #2.78 * 10 ^-4* 10^3# watt-hour
0.278 watt-hours