A lake initially contains $20,000kg$ of water and has a uniform temperature of $20C.$ The ambient pressure is $P=1$ bar. During the course of a day, the following events affecting the lake occur:

$200kg$ of rain falls into the lake. The rainwater has a temperature of $25C.$

Some water evaporates from the lake.

Heat is both added to $($sunlight$)$ and removed from $($convection into the cooler air$)$ the lake.

If you need the heat capacity of LIQUID water, use the approximation $C_V{C}_{P}4\mathrm{.}184\frac{J}{g}*C.$

A$.$ Find a reasonable estimate of the velocity of a raindrop and determine the kinetic energy of the rain when it strikes the lake. Is the kinetic energy significant compared to the enthalpy?

B$.$ The surface of the lake is at $T=20C$ and $P=1$ bar. The enthalpy of water vapor at $T=20C$ and $P=1$ bar is not in the steam tables. You could