How do I start?

Question

Problem: A helium nucleus (m= 6.65 x 10^-27 kg and q = 2e)is initially at rest. It is accelerated through a potential difference delta V and then enters a region with a constant magnetic field of strength B= 4T. It enter perpendicular to the field and undergoes circular motion with a radius of 0.001 m. Determine delta V?

Answer 1

Use the formula for the Larmor radius to get the velocity, v. You will find it at

http://en.wikipedia.org/wiki/Gyroradius

Then compute the kinetic energy of the particle, KE = (1/2) m v^2

Use that to get deltaV

KE = q*(deltaV)

Show your work for further assistance