The correct answer to the question is D). Kinetic to electrical.
EXPLANATION:
Hydro electric power plants are the electricity generation plants which capture the energy of falling water to produce current.
The water present at the top of a dam has potential energy. When the water is allowed to fall from certain height, the potential energy of the water is converted into kinetic energy.
The falling water moving with high speed is allowed to fall on a turbine. The kinetic energy of the water will rotate the turbine. The turbine is attached to a generator which will produce electricity due to the electromagnetic induction.
Hence, we see that the kinetic energy of the water is converted into electric energy.
Answer:
t = 6.68 seconds
Explanation:
The acceleration of the automobile, 
Initial speed of the automobile, u = 91 km/hr = 25.27 m/s
Final speed of the automobile, v = 104 km/hr = 28.88 m/s
Let t is the time taken to accelerate from u to v. It can be calculated as the following formula as :
t = 6.68 seconds
So, the time taken by the automobile to accelerate from u to v is 6.68 seconds. Hence, this is the required solution.
The short answer is that the displacement is equal tothe area under the curve in the velocity-time graph. The region under the curve in the first 4.0 s is a triangle with height 10.0 m/s and length 4.0 s, so its area - and hence the displacement - is
1/2 • (10.0 m/s) • (4.0 s) = 20.00 m
Another way to derive this: since velocity is linear over the first 4.0 s, that means acceleration is constant. Recall that average velocity is defined as
<em>v</em> (ave) = ∆<em>x</em> / ∆<em>t</em>
and under constant acceleration,
<em>v</em> (ave) = (<em>v</em> (final) + <em>v</em> (initial)) / 2
According to the plot, with ∆<em>t</em> = 4.0 s, we have <em>v</em> (initial) = 0 and <em>v</em> (final) = 10.0 m/s, so
∆<em>x</em> / (4.0 s) = (10.0 m/s) / 2
∆<em>x</em> = ((4.0 s) • (10.0 m/s)) / 2
∆<em>x</em> = 20.00 m
