A hydroelectric power plant draws water from a lake whose surface is 55 m above the turbines. It draws the water through a pipe with the radius 1.2 m (Patm = 100kpa, Pwater= 1000 kg/m^-3.
a) If, at point A, 55 m below the surface of the lake , the pipe is horizontal and the water is flowing through itat a rate of 9 m/s^-1, at what pressure is the water? ( Hint: compare this point to the surface of the lake using Bernoulli's Law)
b) In order for the turbines to work most efficiently the water should enter them at aspeed of 20 m/s^-1. In order to achieve this the pipe narrows to what radius just before it enters the turbines?
c) what is the pressure just before the water enters the turbines?