An electron is accelerated from rest through a voltage of

Question

Compute all parts of given question:

Question: An electron is accelerated from rest through a voltage of 300 V and then enters a region of constant magnetic field with the magnetic field perpendicular to the velocity of the electron.

Part A: What is the speed of the electron when it just enters the region of magnetic field?

m/s

Part B: In the region with the magnetic field, the electron follows a circular path in this region. What is radius of the circular path if the magnitude of the magnetic field is 0.38 mT?

cm

Please show me step by step or type in formulas used. I am so lost!!