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Homework Help: Temperature of the water in Fell Beck?

  1. Oct 1, 2011 #1


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    I have a question from a multiple choice test and I am not sure what to do with it. It would be great if you could help me :)

    1. The problem statement, all variables and given/known data

    Estimate the change in temperature of the water in Fell Beck before and after it falls into the Gaping Gill pothole (depth 105 m). The specific heat capacity of water is 4.2 kJ/(kg*K).

    A) 4 °C
    B) 0.25 °C
    C) 0.0025 °C
    D) 9.2 * 10^-4 °C

    2. Relevant equations

    C = m * c

    C: Heat capacity
    c: Specific heat capacity

    Q = C * ΔT

    Q: Heat transfer

    3. The attempt at a solution

    I'm not really sure how to find the mass of the water? Or the energy?
    The time I can find (105m = 1/2 * 10m/s^2 * t^2) and the rest I've got the formulas for.

    Thank you for the help :)
    Last edited: Oct 1, 2011
  2. jcsd
  3. Oct 1, 2011 #2


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    Staff: Mentor

    You can assume a particular quantity of water to work with. 1kg is a nice value :smile: Or you can work with "specific" values, which here means "per unit mass". So for example, the change in energy might be x Joules per kg. This bypasses having to deal with a particular value of mass.

    Conservation of energy (gravitational potential energy vs kinetic energy) might be the quickest route to finding your energy due to the fall.
  4. Oct 2, 2011 #3


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    Thank you very much :)
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