Part 1:

A proton is moving in a circular orbit of radius 12.6 cm in a uniform 0.27-T magnetic field perpendicular to the velocity of the proton.

a) the angular speed of the proton= 2.5 x 10^7 rad/s

b) the magnetic field force = 1.40 x 10^-13

c) linear acceleration a= 8.429 x 10^13 m/s^2

d) the kinetic energy= 8.869 x 10^15 J

Question:

Assume particle to be an electron, rather than a proton, moves in a direction perpendicular to the same magnetic field. Since mass of electron is much smaller than proton, what velocity (for electron) should be used to maintain same radius as proton given in part 1?