A small stream with $20\backslash$deg C water runs out over a cliff, creating a $100-$m$-$tall $\frac{x}{?}$waterfall. Estimate the downstream temperature when you neglect the horizontal flow velocities upstream and downstream from the waterfall.

How fast was the water dropping just before it splashed into the pool at the bottom of the waterfall?

How high will the cliff have to be for the downstream water temperature to be $80$ deg$/$C$.$