The energy from the sun is what sustains the solar system. But this is only a small part of the universe. So it will be inaccurate to say that the source of all energy in the universe is the sun.
<span>The universe is made up of several other galaxies including our own milky way. But looking at these components of the universe, they are made up of stars. Considering that all other stars are similar to our sun, which by the way is also a star, then we can put it that their collective energies is what constitutes the energy source for the universe. </span>
<span>But here we have only considered what we know about the universe, since man has been able to explore only a minute fraction of the universe, it wont be fair to argue that this is absolute. There may be other energy sources out there that have not yet been discovered, but for now, the idea behind the summation of celestial energies should suffice. </span>
Answer: 0.016 h
Explanation:

It is given that, biker has an average speed = 18 km/h
Total distance traveled = 0.30 km
Therefore, time taken by biker to travel this distance:

Thus, the biker takes 0.016 hours to travel the segment of 0.30 km at an average speed of 18 km/h.
Answer:
t = 1964636.542 sec
Explanation:
Given data:
sphere diameter is 10 mm
Density is 1150 kg/m^3
viscosity 105 N s/m^2
We knwo that time taken by sphere can be calculated by following procedure



Solving for du




When silver is poured into the mould the it will solidify
In this process the phase of the Silver block will change from liquid to solid.
This phase change will lead to release in heat and this heat is known as latent heat of fusion.
The formula to find the latent heat of fusion is given as

here given that


now we can find the heat released


So it will release total heat of 55.5 kJ when it will solidify
C) explore alternative sources of energy, such as solar energy