Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Heating water using Watts

  1. Dec 4, 2006 #1
    1. The problem statement, all variables and given/known data
    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


    3. 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?
     
    Last edited: Dec 4, 2006
  2. jcsd
  3. Dec 4, 2006 #2

    berkeman

    User Avatar

    Staff: Mentor

    I didn't check the math, but it looks like your approach is correct.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook