Power Vs.heat

Most recent answer: 03/12/2008

Q:
If it takes 1 calorie to raise the temp of 1 gram of water by 1 degree c, what is a calorie in watts and is this watts of power or heat?
- Darrell Griffiths
Bandon Co cork Rep of Ireland
A:
Watts are a measure of power- the rate at which energy is flowing, not the total amount of energy transferred. The difference is like the difference between miles per hour and miles. A Watt is one Joule per second. A calorie is a little more than 4 Joules. So you can raise the temperature of a gram of water by 1°C in a little more than 4 seconds with a 1 Watt heater.
Mike W.

(published on 03/12/2008)