How long will it take to melt ice in the microwave?

Question

If you fill a cup with ice, about half the volume is ice and half is air. Assuming this, how can you estimate how long it will take to melt the ice in your microwave set on "high."

Answer 1

how big is the cup?

you can measure it much faster than i can calculate it!

1/2 cup = 4 oz volume measure = 120ml

120ml = 0.00012 m³

0.00012 m³ x 998 kg/m³ = 0.12 kg

specfic heat of water is 4200 J/kgC

heat of fusion of ice is 334 kJ/kg

0.12 kg x 334 kJ/kg = 40000 J

Microwaves are about 1000 watts, which is 1000 J/s

40000 J / 1000 J/s = 40 seconds.

Answer 2

Different microwaves have different power ratings. My suggestion is for you to try out this experiment yourself and noting what the power rating of the microwave oven that  you used.

You can do this test for, say, 3 times to determine the repeatability factor. After you have gathered your data for this particular test of yours, you can now extrapolate your results to predict/calculate the time it will take to melt ice using microwaves of different power ratings.

Answer 3

why dont you try it?  Thats even better than an estimate!

Answer 4

If the micrwave produces about 1000 Watts of energy into the Ice that is 1000 joules/second  Then you need to know the mass of the ice and the enthalpy of fusion being 333 joules/gram

So if the mass is X grams then it will take

333X/1000 = seconds to melt ice  or about 1/3 second per gram of ice