1. The problem statement, all variables and given/known data Assuming no heat is transferred to or from the surroundings, how much does the temperature of a river rise in going over a 30 m falls? (assume the velocity of the water is the same above and below the falls) 2. Relevant equations Δl = αlΔT 3. The attempt at a solution H = 0 and l = 30. I do not know where to go from there. I also do not know alpha.