# Heat and internal energy

1. Sep 10, 2010

### mizzy

1. The problem statement, all variables and given/known data
Water at the top of Niagara Falls has a temperature of 10.0degrees celsius. If it falls a distance of 50.0m and all of its potential energy goes into heating the water, calculate the temperature of the water at the bottom of the falls.

2. Relevant equations

W = change in kinetic energy + change in potential energy

3. The attempt at a solution
i know there's potential energy on top and none at the bottom. There's not kinetic energy at the top and there is at the bottom. But how do i put temperature into this equation???

2. Sep 10, 2010

### rock.freak667

The change in potential energy of the water = heat absorbed by water

You should know the equation Q=mcΔT

3. Sep 10, 2010

### mizzy

so distance isn't included in the equation? and mass?

4. Sep 10, 2010

### rock.freak667

The height is a distance and the mass will not really matter.

5. Sep 11, 2010

### mizzy

so, mgh = mc(T-Ti)

then solve for Tf?

therefore,

mgh = mc(Tf - Ti)
gh = cTf - cTi
gh + cTi = cTf
gh/c + Ti = Tf

6. Sep 11, 2010

### rock.freak667

Yes that should work.

7. Sep 11, 2010

Thanks