-- The source of most of the energy that radiates from the sun is nuclear energy.
-- Most of the energy that radiates from the sun is electromagnetic energy.
-- Heat energy is part of the electromagnetic energy that radiates from the sun.
Other parts include radio, microwave, visible light, ultraviolet, and X-ray energy.
Explanation:
It is given that,
The volume of a right circular cylindrical, 
We know that the volume of the cylinder is given by :

............(1)
The upper area is given by :



For maximum area, differentiate above equation wrt r such that, we get :



r = 1.83 m
Dividing equation (1) with r such that,



Hence, this is the required solution.
In object in motion stays in motion; speed
I am not sure but i think the answer is C