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: Help with physics calc

  1. Jul 30, 2007 #1
    When Adam drinks cold water, his body warms the water until thermal equilibrium is reached. If he drinks six glasses (2.5 kilograms) of water at 0 degrees Celsius in a day, approximately how much energy must his body expend to raise the temperature of this water to his body’s temperature of 37 degrees Celsius?
    The answer is 390kJ. Can someone help me with the working please. Thx.
  2. jcsd
  3. Jul 30, 2007 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    WHat is the heat capacity of water? i.e., how much energy is required to raise one kilogram of water by one degree Celsius?
  4. Jul 30, 2007 #3
    The heat capacity was not given in the question but if we assume it to be pure water, the heat capcity of water can be taken as 4.184 joules/g-°C.
  5. Jul 31, 2007 #4
    4.184 joules/(g°C) * 2.5 kg * 37 ° C = ... :)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook