A proton is accelerate from rest through a potential difference of 1kv. It enters a uniform magnetic field of 4.5mT that is perpendicular to the direction of its motion. (a) Find the radius of he circular path of the proton. (b) calculate the period of revolution of the proton.

Question

anonymous · Answer

From the potential difference you know the protons kinetic energy (see definition voltage), from this information and the mass of a proton you can calculate it's speed (E_kin = m*v²/2). 

Once the proton enters the magnetic field you have an object that is moving in a circle at a constant speed. How is that possible? Well, it must have a force acting upon it. What force do you think that might be?

anonymous · Answer

( m*v^2/2 )