U can also add solar energy and hydro energy. Solar energy is by using the sun, while hydro is by using the force of water.
This is how hydro energy works:
its is usually built near a waterfall, OK so when the water falls of the cliff of the water fall , it creates a force which helps turn the generator and then it is carried into poles of electricity.
Hope this helps plus i gave u extra point Good luck :)
Answer: 
Explanation:
Given
Mass of child 
speed of child is 
Moment of inertia of merry go round is 
radius 
Conserving the angular momentum
Gravitational force is the weight of the object, therefore weight=mass*gravitational field strength=10*9.8=98N therefore the answer is D
The answer is 138.75 kgm/s
Impulse (I) is the multiplication of force (F) and time interval (Δt): I = F · Δt
It is given:
m = 0.25
F = 18,500 N = 18,500 kgm/s²
Δt = 0.0075 s
I = ?
I = F · Δt = 18,500 5kgm/s² * 0.0075 s = 18,500 * 0.0075 kgm/s² * s = 138.75 kgm/s
