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:
4 times the mass of Earth
Explanation:
= Mass of Earth
= Mass of the other planet
r = Radius of Earth
2r = Radius of the other planet
m = Mass of object
The force of gravity on an object on Earth is

The force of gravity on an object on the other planet is

As the forces are equal

So, the other planet would have 4 times the mass of Earth
Answer:

Explanation:
= Activation energy = 160 kJ
T = Temperature = 510 K
R = Universal gas constant = 8.314 J/mol K
The fraction of energy is given by

The fraction of energy is 
Answer:
50.4÷1.18= 42.7m/s as speed is equal to the distance over the time taken
Answer:
Explanation:
Given that a coil has a turns of
N = 110 turns
And the flux is given as function of t
ΦB = 9.75 ✕ 10^-3 sin(ωt),
Given that, at an instant the angular velocity is 8.70 ✕ 10² rev/min
ω = 8.70 ✕ 10² rev/min
Converting this to rad/sec
1 rev = 2πrad
Then,
ω = 8.7 × 10² × 2π / 60
ω = 91.11 rad/s
Now, we want to find the induced EMF as a function of time
EMF is given as
ε = —NdΦB/dt
ΦB = 9.75 ✕ 10^-3 sin(ωt),
dΦB/dt = 9.75 × 10^-3•ω Cos(ωt)
So,
ε = —NdΦB/dt
ε = —110 × 9.75 × 10^-3•ω Cos(ωt)
Since ω = 91.11 rad/s
ε = —110 × 9.75 × 10^-3 ×91.11 Cos(91.11t)
ε = —97.71 Cos(91.11t)
The EMF as a function of time is
ε = —97.71 Cos(91.11t)
Extra
The maximum EMF will be when Cos(91.11t) = -1
Then, maximum emf = 97.71V