3. Use the Penman combination equation to estimate evaporation from a (water) surface for the following conditions: temperature of the surface, To = 290 K; air temperature, Ta= 300 K; relative humidity, r.h. = 50%; wind speed, u₂ = 3 mph; surface pressure, p = 100000 Pa; roughness length, zo = 0.0001 m; net available energy, Q = 180 W/m².