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
given,
v = (6 t - 3 t²) m/s
we know,


position of the particle

integrating both side

x = 3 t² - t³
Position of the particle at t= 3 s
x = 3 x 3² - 3³
x = 0 m
now, particle’s deceleration


a = 6 - 6 t
at t= 3 s
a = 6 - 6 x 3
a = -12 m/s²
distance traveled by the particle
x = 3 t² - t³
at t = 0 x = 0
t = 1 s , x = 3 (1)² - 1³ = 2 m
t = 2 s , x = 3(2)² - 2³ = 4 m
t = 3 s , x = 0 m
total distance traveled by the particle
D = distance in 0-1 s + distance in 1 -2 s + distance in 2 -3 s
D = 2 + 4 + 2 = 8 m
average speed of the particle



Answer:
Mass of natural gas needed to heat the room is 350,000BTUs
Explanation:
The heating efficiency of a furnace is never 100% because not all energy is released and not all heat is available to heat the place. A lesser efficiency requires more consumption of fuel. Heating values are used for heating fuels in order to calculate the mass of fuel needed.
The heating value of natural gas is 1,000,000BTUs
Therefore the formular for calculating mass of natural gas needed= Heating value of natural gas×efficiency.
Mass=1,000,000×0.35
Mass=350,000BTUs
Answer:
The magnitude of electric field is
in downward.
Explanation:
Given that,
Force 
Charge q= -2.00 μC
We know that,
Charge is negative, then the electric field in the opposite direction of the exerted force.
We need to calculate the magnitude of electric field
Using formula of electric force




Negative sign shows the opposite direction of electric force.
Hence, The magnitude of electric field is
in downward.
Answer - corona, chromosphere, photosphere