Answer:
The maximum electric power output is

Step-by-step explanation:
From the question we are told that
The capacity of the hydroelectric plant is

The level at which water is been released is

The efficiency is
0.90
The electric power output is mathematically represented as
Where
is the potential energy at level h which is mathematically evaluated as

and
is the potential energy at ground level which is mathematically evaluated as


So
here

where V is volume and
is density of water whose value is

So

substituting values


The maximum possible electric power output is

substituting values

