Kinetic Energy is calculated by KE= 1/2mv2
Answer:
Charge, 
Explanation:
It is given that,
The number of electron in a RBCs, 
We need to find the total charge of these electrons in the red blood cell. Let it is q. Using the quantization of charge as follows :
q = ne
e is the change on electron

So, the net charge is
.
Direction of resultant force in circular motion is directed towards the center of the circle. Hence vector B is the direction of the resultant force.