Answer:
The maximum electric power output is 
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


Answer: The observing friend will the swimmer moving at a speed of 0.25 m/s.
Explanation:
- Let <em>S</em> be the speed of the swimmer, given as 1.25 m/s
- Let
be the speed of the river's current given as 1.00 m/s.
- Note that this speed is the magnitude of the velocity which is a vector quantity.
- The direction of the swimmer is upstream.
Hence the resultant velocity is given as,
= S — S 0
= 1.25 — 1
= 0.25 m/s.
Therefore, the observing friend will see the swimmer moving at a speed of 0.25 m/s due to resistance produced by the current of the river.
So the acceleration of gravity is 9.8 m/s so that’s how quickly it will accelerate downwards. You can use a kinematic equation to determine your answer. We know that initial velocity was 19 m/s, final velocity must be 0 m/s because it’s at the very top, and the acceleration is -9.8 m/s. You can then use this equation:
Vf^2=Vo^2+2ax
Plugging in values:
361=19.6x
X=18 m
The charge of the object must be 
Answer: Option C
<u>Explanation:</u>
Suppose an electric charge can be represented by the symbol Q. This electric charge generates an electric field; Because Q is the source of the electric field, we call this as source charge. The electric field strength of the source charge can be measured with any other charge anywhere in the area. The test charges used to test the field strength.
Its quantity indicated by the symbol q. In the electric field, q exerts an electric, either attractive or repulsive force. As usual, this force is indicated by the symbol F. The electric field’s magnitude is simply defined as the force per charge (q) on Q.

Here, given E = 4500 N/C and F = 0.05 N.
We need to find charge of the object (q)
By substituting the given values, we get

Answer:
Explanation:
Energy E is conserved:

If v₀ = 22m/s, h₀=0m and h₁=25m:

Solving for v₁:

There is no real solution, because the stone never reaches 25m.