At a bottled water plant, water with a density of 1.00 g/ml passes through a pumping station where it is raised vertically by 5.00 m at the rate of 1,910,000 liters per day. The liquid enters and leaves the pumping station at the same speed and through pipes of equal diameter. (a) Determine the output mechanical power (in W) of the lift station. Ignore any energy loss due to friction. (b) Assume an electric motor continuously operating with average power 3.85 kW runs the pump. Find its efficiency.

A small aircraft has a wing area of 35 m2, a lift coefficient of 0.45 at takeoff settings, and a total mass of 4000 kg. Determine (a) the takeoff speed of this aircraft at sea level at standard atmospheric conditions, (b) the wing loading, and (c) the required power to maintain a constant cruising speed of 300 km/h for a cruising drag coefficient of 0.035.

46. A power output of 18.0 h.p. is required to overcome friction and move a certain car at a constant speed of 55.0 mph. The car runs on gasoline that has an energy content of 110 MJ per gallon. The efficiency of the engine/transmission is 15%. (a) What is the force of friction on the car? (b) What power input is required at 55.0 mph? (c) How much energy is wasted every minute at 55.0 mph? (d) Determine the fuel economy in miles per gallon.

A student evaluates a weight loss program by calculating the number of times he would need to climb a 11.0 m high flight of steps in order to lose one pound (0.45 kg) of fat. Metabolizing 1.00 kg of fat can release 3.77 ✕ 107 J of chemical energy and the body can convert about 21.8% of this into mechanical energy (the rest goes into internal energy.) (a) How much mechanical energy (in J) can the body produce from 0.450 kg of fat?   (b) How many trips up the flight of steps are required for the 56.0 kg student to lose 0.450 kg of fat? Ignore the relatively small amount of energy required to return down the stairs.