# Physics

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River Dam generates electricity with water taken from a depth of 110 m and with an average flow rate of 740 m3/s.

a) Calculate the power in this flow. Note that the velocity and height of the water are not changed appreciably by the generators, and the pressure at the exit point is at atmospheric level. Take the density of water to be 1000 kg/m3.

b) What is the speed of the water at the exit point?

c) What is the radius of the exit hole in the dam?

• Physics -

Density of water = 1000 kg/m^3
pressure difference = density *g * h =10^3*9.81*110 = 1.08*10^6 Newtons/m^2
power = pressure*Q = 1.08*10^6 * 740
= 8*10^8 Joules meters/second or Watts
or 800 megawatts

b) (1/2) rho v^2 = rho g h
v = sqrt (2 g h)

c) pi r^2 v = 740

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