they are called "cells"
hope this is the answer is what your looking for.
Answer:
D
Explanation:
Work is not a vector but it is a scalar
Answer:
Part a)

Part b)

Explanation:
Part a)
As we know that both charge particles will exert equal and opposite force on each other
so here the force on both the charges will be equal in magnitude
so we will have

here we have

now we have

Part b)
Now for the force between two charges we can say

now we have

now we have
