Physics Van 3-site Navigational Menu

Physics Van Navigational Menu

Q & A: microwave heating times

Learn more physics!

Most recent answer: 04/08/2008
I have a microwavable heating pad that lists a series of 'watts per time' to sufficiently heat the pad. 1200 watts would be 45 seconds to 'heat' 1000 watts 60 seconds 800 watts 75 seconds 600 watts 90 seconds Problem is, my microwave has only a series of letters and numbers with no actual listing of 'wattage'. All it says is 120 volts, after searching for several hours I've determined nothing about the relative difference so I heated the pad for 90 seconds and it seems to have worked. However, I'd still like to know the propper conversion rate, so that I dont cause my heating pad to explode from impropper 'heating'.
- Joshua (age 24)
Wichita KA
If you search the Web for specs on your microwave, you'll probably find some specified wattage.  Meanwhile what you've done- the actual experiment- sounds more reliable. If you switch microwaves, I suggest starting with some short time, say 30 sec, and and then seeing how much additional time is needed, feeling the pad before further heating in stages. Just in case the power is high, you don't want to start with a long time.

Mike W.

(published on 04/08/2008)

Follow-up on this answer.