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Heat and internal energy

  • Thread starter caesius
  • Start date
  • #1
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Homework Statement


On his honeymoon, James Joule tested the conversion of mechanical energy into internal energy by measuring temperatures of falling water. If water at the top of a Swiss waterfall has a temperature of 10.0 degrees Celsius and then falls 50.0 m, what maximum temperature at the bottom could Joule expect?


Homework Equations



change in internal energy = mgh


The Attempt at a Solution



I'm sure this question is easy I must be missing something, the change in internal energy is mgh but we have no mass?

The answer is (10.0 + 0.117) but I don't see how this was found.
 

Answers and Replies

  • #2
olgranpappy
Homework Helper
1,271
3
use
[tex]
\Delta E = c M \Delta T
[/tex]
where c is the specific heat. the mass drops out.
 

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