Atoms are basically tiny structures that make up everything. And a compound is something used in a scientific expirement. I don't get the question. You used improper grammar
Answer:
c. V = 2 m/s
Explanation:
Using the conservation of energy:

so:
Mgh = 
where M is the mass, g the gravity, h the altitude, I the moment of inertia of the pulley, W the angular velocity of the pulley and V the velocity of the mass.
Also we know that:
V = WR
Where R is the radius of the disk, so:
W = V/R
Also, the moment of inertia of the disk is equal to:
I = 
I = 
I = 10 kg*m^2
so, we can write the initial equation as:
Mgh = 
Replacing the data:
(5kg)(9.8)(0.3m) = 
solving for V:
(5kg)(9.8)(0.3m) = 
V = 2 m/s
Answer:
Zero because the applied force is perpendicular to the motion of the object.
No work is done on an object moving is a circular path about a central attractive force.
Any work done in such a case would result in a change in the orbit.