Consider a river flowing toward a lake at an average velocity of 3 m/s at a rate of 500 m^3/s at a location 90 m above the lake surface. Determine the total mechanical energy of the river water per unit mass and the power generation potential of the entire river at that location.

Consider a river flowing toward a lake at an average velocity of $3 \mathrm{~m} / \mathrm{s}$ at a rate of $500 \mathrm{~m}^{3} / \mathrm{s}$ at a location $90 \mathrm{~m}$ above the lake surface. Find the total mechanical energy of the river water per unit mass and the power generation potential of the entire river at that location.

At a certain location, wind is blowing steadily at 10 m/s. Determine the mechanical energy of air per unit mass and the power generation potential of a wind turbine with 60-m-diameter blades at that location. Take the air density to be 1.25 kg/m^3.

A 3-m-high tank filled with water has a discharge valve near the bottom and another near the top. (a) If these two valves are opened, will there be any difference between the discharge velocities of the two water streams? (b) If a hose whose discharge end is left open on the ground is first connected to the lower valve and then to the higher valve, will there be any difference between the discharge rates of water for the two cases? Disregard any frictional effects.

A Pitot-static probe is used to measure the speed of an aircraft flying at 3000 m. If the differential pressure reading is 3 kPa, determine the speed of the aircraft.

Consider a river flowing toward a lake at an average speed of $3 \mathrm{~m} / \mathrm{s}$ at a rate of $500 \mathrm{~m}^3 / \mathrm{s}$ at a location $55 \mathrm{~m}$ above the lake surface. Find the total mechanical energy of the river water per unit mass and the power generation potential of the entire river at that location.

Electric power is to be generated by installing a hydraulic turbine-generator at a site 120 m below the free surface of a large water reservoir that can supply water at a rate of 1500 kg/s steadily. Determine the power generation potential.

A small electrical motor produces 5 W of mechanical power. What is this power in (a) N, m, and s units; and (b) kg, m, and s units?

A water jet that leaves a nozzle at 60 m/s at a flow rate of 120 kg/s is to be used to generate power by striking the buckets located on the perimeter of a wheel. Determine the power generation potential of this water jet.

Determine the specific potential energy, in kJ/kg, of an object 50 m above a datum in a location where $g$= 9.8 m/s^2.

Electric power is to be generated by installing a hydraulic turbine–generator at a site 110 m below the free surface of a large water reservoir that can supply water steadily at a rate of 900 kg/s. If the mechanical power output of the turbine is 800 kW and the electric power generation is 750 kW, determine the turbine efficiency and the combined turbine–generator efficiency of this plant. Neglect losses in the pipes.

Calculate the total potential energy, in Btu, of an object that is 20 ft below a datum level at a location where $g$= 31.7 ft/s^2 and which has a mass of 100 lbm.

Water is being heated in a closed pan on top of a range while being stirred by a paddle wheel. During the process, 30 kJ of heat is transferred to the water, and 5 kJ of heat is lost to the surrounding air. The paddle-wheel work amounts to 500 Nm. Determine the final energy of the system if its initial energy is 12.5 kJ.

Calculate the total potential energy, in Btu, of an object with a mass of 200 lbm when it is 10 ft above a datum level at a location where standard gravitational acceleration exists.