Results are out! Find what you need...fast. Get quick advice or join the chat
Hey! Sign in to get help with your study questionsNew here? Join for free to post

mixing ratio

Announcements Posted on
The Grow your Grades contest is here, join in to help each other achieve your study goals 22-01-2015
  1. Offline

    ReputationRep:
    Hi,
    how would I go about working this problem out:

    3 units of water that are 5oC mix with 2 units of water that are 10oC, what is the resultant temperature of the mixture?

    thanks
  2. Online

    ReputationRep:
    (Original post by mchammer)
    Hi,
    how would I go about working this problem out:

    3 units of water that are 5oC mix with 2 units of water that are 10oC, what is the resultant temperature of the mixture?

    thanks
    (3 x 5) + (2 x 10) = 15 + 20 = 35, so 35 is the 'total temperature'

    There are 5 units, so for the mean temperature, you do 35/5 = 7oc.
  3. Offline

    ReputationRep:
    (Original post by thegodofgod)
    (3 x 5) + (2 x 10) = 15 + 20 = 35, so 35 is the 'total temperature'

    There are 5 units, so for the mean temperature, you do 35/5 = 7oc.
    That would be incorrect.

    (Original post by mchammer)
    Hi,
    how would I go about working this problem out:

    3 units of water that are 5oC mix with 2 units of water that are 10oC, what is the resultant temperature of the mixture?

    thanks
    I'm assuming the specific heat capacity of water = 4.2 J/g degC

    The temperature of the 3 unit setup is higher than that of the 2 unit setup. Hence, when mixed together, thermal energy will flow from the 3 units to the 2 units until both are at equal temperatures.

    3*4.2*(50-T) = 2*4.2*(T-10)

    T = final temperature.
  4. Offline

    ReputationRep:
    I would probably use kelvin for this. I'm not sure if it makes a difference, but 50°C is not 5 times as hot as 10°C and therefore doesn't contribute 5x the energy.
  5. Offline

    ReputationRep:
    (Original post by Repressor)
    I would probably use kelvin for this. I'm not sure if it makes a difference, but 50°C is not 5 times as hot as 10°C and therefore doesn't contribute 5x the energy.
    It wouldn't make a difference since a change in temp. of 1 K = a change of temp. of 1 deg C

Reply

Submit reply

Register

Thanks for posting! You just need to create an account in order to submit the post
  1. this can't be left blank
    that username has been taken, please choose another Forgotten your password?
  2. this can't be left blank
    this email is already registered. Forgotten your password?
  3. this can't be left blank

    6 characters or longer with both numbers and letters is safer

  4. this can't be left empty
    your full birthday is required
  1. By joining you agree to our Ts and Cs, privacy policy and site rules

  2. Slide to join now Processing…

Updated: May 27, 2012
New on TSR

Everyday things you can't do

Why do they make everything so difficult?

Article updates
Quick reply
Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.