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April 30, 2016

# Homework Help: Physics

Posted by Oddbjørn on Thursday, December 2, 2010 at 2:31pm.

Hello agein, a biger question this time.

Height difference H 180 meters
Flow T 3000 tons / second
Delivery 4.2 GW P

a)
How large is the efficiency of the plant through the turbines?

b)
From turbine power plant goes through a cable stretch over a long stretch. The efficiency of this stretch is estimated to be 0.62 (62%).

How much effect can be taken out of a maximum cable migration on the supply side?

c)
How large is the overall efficiency of the plant from the dam to the delivery point

• Physics - drwls, Thursday, December 2, 2010 at 4:12pm

Are you talking metric tons (1000 kg) or USA tons (2000 lbm)?

a) Divide the rate of (water) potential energy loss to the electrical output of the turbine. Use consistent units

efficiency = 4.2*10^9 W/(dM/dt)*g*H)

dM/dt is the mass flow rate; H is the height of reservoir water above the turbine intake.

If your tons are metric, I get 79.4%

b) I have no idea what you mean by "taking effect out of cable migration"