Answer : 
Explanation :
Given that
Radius of sphere 
The distance between the centers of the two spheres is

The charge of the sphere 
The magnitude of the repulsive force between the charges pushing them a part is
Using coulomb law




Hence, this is the required solution.
Acceleration is the rate of change in an object's velocity
I think the correct answer from the choices listed above is option B. It is the electrons that flow because of electrical attraction and repulsion causes an electric current in a wire. Electrons, which continuously move in wire, are called Electric Current. Hope this answers the question.
A is only the area of one tile. It wants the area of the whole floor.
area of parallelogram is b*h=0.952. There are 9500 of them so 0.952*9500=904.4 (answer c)