Consider a river flowing toward a lake at an average speed of 3m/s at a rate of 500 m^3/s at a location 58m above the lake surface. determine the total mechanical energy of the river water per unit mass (in kj/kg) and the power generation potential of the entire river at that location (in mw). the density of water is 1000 kg/m^3, and the acceleration due to gravity is 9.81 m/s^2.