<span>Answer:
I'm pretty sure the SA / V ratio would get smaller. Assume that the cell is more or less spherical. SA = 4(pi)r^2, while V = (3/4)(pi)r^3. The ratio = (4(pi)r^2)/((3/4)(pi)r^3), which can be simplified to 3/r. Thus, the larger r gets, the smaller the ratio becomes.</span>
Force on a moving charge is given by formula

here we know that this force will be maximum when velocity is perpendicular to magnetic field

here we know that



now we have


Kinetic energy is the energy associated with the motion of an object. It's a scalar quantity, there is no direction associated with KE and it has no components.

.
Therefore Kinetic energy is 817.96J.