How Long to Heat 250g of Water with a 250-Watt Heater?

[wakejosh]

Homework Statement

its a long story problem so ill break it down:
an electric heater generates 250 Watts of electricity, how long will it take for 250 grams of water to heat from 20 C to 80 C

The Attempt at a Solution

so 80 C - 20 C = 60 C , i have to heat it 60 C
250 grams of water X 60 C = 15000 Calories
4.184 X 15000 = 62760 Joules

62760 J / 250 watts = 251 seconds / 60 = 4.18 min

so it will take 4.18 min. Is this correct?

 

[berkeman]

I didn't check the math, but it looks like your approach is correct.