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: Please helpppppppppppppppppppppppppppp

  1. Nov 12, 2007 #1
    1. The problem statement, all variables and given/known data

    How much water at 82 degrees celsius must be added to 1.00kg of water at 14 degrees celsius to give it a final temperature of 36 degrees celsius

    2. Relevant equations

    qgained=-qlost???????

    3. The attempt at a solution
    finding the resulting temperature, never works out for me please help
     
  2. jcsd
  3. Nov 12, 2007 #2
    If added 1 kg of water at 16 degress to the 1 kg of water at 14 degrees, what would you expect the temperature of the resulting 2 kg of water to be?
     
    Last edited by a moderator: Nov 12, 2007
  4. Nov 12, 2007 #3

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    Suppose it takes X joules of energy to raise 1Kg of water 1 degree.
    You need to increase 1Kg of water by 36-14 = 22 degrees.
    You are going to do this by adding water that is 82-14 = 68 degrees hotter.
    Then it's just a matter of ratios.

    Suppose you added 1Kg it would end up at half way between 14 and 86 = 14 + (86-14)/2 = 50deg so you need less than 1kg
     
  5. Nov 12, 2007 #4
    Where is your work?

    Perhaps to get started, are you aware of this formula?
    [tex]
    m_1 c_1 \left( {T_1 - T_F } \right) = m_2 c_2 \left( {T_F - T_2 } \right)
    [/tex]
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook