Answer:
The alternative energy sources are defined as those resources that are used in place of the natural and non-renewable resources. This resources plays an important role in the conservation of natural resources.
The fossil fuels are the resources on which the people are directly dependent. Burning up of these fossils leads to the emission of carbon, which has a direct impact on earth. A small increase in the amount of carbon dioxide can lead to the increase in the surface temperature of earth.
In addition to this, these fossil fuels such as coal, petroleum, oil and natural gases are found to be present in a limited proportion, and it is a very expensive process to obtain these resources, so sustainable development method must be adopted in order to save this natural resources for the future generation.
Some of the examples of alternative resources that are widely used in place of fossil fuels are wind energy, solar energy, tidal energy, biomass energy and bio-fuels.
Thus, it is very important to develop and use alternative resources.
Answer:given below by him is correct
Explanation:
Pls refer his
If all the mass of fuel and oxygen is burned to form gases of combustion, the downward velocity of these gases would be 12,505 m/s.
<h3>
Conservation of linear momentum</h3>
The principle of conservation of linear momentum states that, the total momentum of an isolated system is constant.
The downward velocity of thes gases is calculated as follows;
v1(m1 + m2) = v2(m2)
305(1000 + 25) = v2(25)
312,625 = 25v2
v2 = 312,625/25
v2 = 12,505 m/s
Thus, If all the mass of fuel and oxygen is burned to form gases of combustion, the downward velocity of these gases would be 12,505 m/s.
Learn more about linear momentum here: brainly.com/question/7538238
Given that,
Energy 
Surface temperature = 11000 K
Emissivity e =1
(a). We need to calculate the radius of the star
Using formula of energy



Put the value into the formula


(b). Given that,
Radiates energy 
Temperature T = 10000 K
We need to calculate the radius of the star
Using formula of radius

Put the value into the formula


Hence, (a). The radius of the star is 
(b). The radius of the star is 
Answer:
A) True, B) False, C) False and D) false
Explanation:
Let's solve the problem using the law of conservation of energy to know if the statements are true or false
Let's look for mechanical energy
Initial
Emo = Ke = ½ k Dx2
Final
Em1= ½ m v12
Emo = Em1
½ k Δx2 = ½ m v₁²
v₁² = k / m Δx²
v₁ = √ k/m Δx
Now let's calculate the speed when it falls
Vfy² = Voy² - 2gy
Vfy² = - 2gy
Vf² = v₁² + vfy²
A) True v₁ = A Δx
.B) False. As there is no rubbing the mechanical energy conserves
.C) False the velocity is proportional to the square root of the height
v2y = v2 √2
. D) false promotional compression speed