The hydropower plant and wind turbines both uses kinetic energy to produce mechanical power and convert the mechanical energy using a generator to an electrical energy. They both have the process to produce energy but they differ in the source the hydropower plant uses water to whit the wind turbines power plant uses wind. Therefore the answer is letter B.
(a) The ball's height <em>y</em> at time <em>t</em> is given by
<em>y</em> = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
where <em>g</em> = 9.80 m/s² is the magnitude of the acceleration due to gravity. Solve <em>y</em> = 0 for <em>t</em> :
0 = (20 m/s) sin(40º) <em>t</em> - 1/2 <em>g t</em> ²
0 = <em>t</em> ((20 m/s) sin(40º) - 1/2 <em>g t</em> )
<em>t</em> = 0 or (20 m/s) sin(40º) - 1/2 <em>g t</em> = 0
The first time refers to where the ball is initially launched, so we omit that solution.
(20 m/s) sin(40º) = 1/2 <em>g t</em>
<em>t</em> = (40 m/s) sin(40º) / <em>g</em>
<em>t</em> ≈ 2.6 s
(b) At its maximum height, the ball has zero vertical velocity. In the vertical direction, the ball is in free fall and only subject to the downward acceleration <em>g</em>. So
0² - ((20 m/s) sin(40º))² = 2 (-<em>g</em>) <em>y</em>
where <em>y</em> in this equation refers to the maximum height of the ball. Solve for <em>y</em> :
<em>y</em> = ((20 m/s) sin(40º))² / (2<em>g</em>)
<em>y</em> ≈ 8.4 m
Lo experiences tidal heating primarily because lo’s elliptical orbit causes the tidal force on lo to vary as it orbits the Jupiter. Thus, lo’s elliptical orbit is essential to its tidal heating. This elliptical orbit, in turn, is an end result of the orbital resonance among lo, Europa and ganymade. This orbital resonance origin lo to have a more elliptical orbit than it would because lo intermittently passes Europa and ganymade in the same orbital position. We cannot perceive tidal forces of tidal heating in lo but rather we foresee that they must occur based on the orbital characteristic of the moons and active volcanoes on lo is the observational evidence that tidal heating is significant in lo.
The correct answer is electromagnetic. Lights travel as an electromagnetic wave. In fact, light is an electromagnetic radiation which has a center of the electromagnetic spectrum. Light is visible to the naked eye, and is responsible for an organism's sense of sight.
Answer:
19.6m/s
Explanation:
A Rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for certain period of time, for such motion following equation of motion can be used.
here in our case 
because object starts off from rest and 
is acceleration because of gravity ( Motion under gravity).
and of course t = 2 second.
Now by substituting all this information in equation of motion we get.
that would be the velocity of rock as it would hit the ground.
Note! We have assumed that there is no air resistance.
A rock falling off a cliff can be modeled as an object starting with zero velocity moves with constant acceleration for a certain period of time, for such motion following equation of motion can be used.
here in our case because object starts off from rest and is acceleration because of gravity ( Motion under gravity).
and of course t = 2 seconds.
Now by substituting all this information in equation of motion we get.
V = 19.6m/s
that would be the velocity of rock as it would hit the ground.
Note! We have assumed that there is no air resistance.
