How Does a Proton Move in a Magnetic Field?

[aurora14421]

Homework Statement

A proton enters a uniform magnetic field of strength B. Sketch it subsequent motion and derive an expression for the time, t, spent in the magnetic field.

Homework Equations

$$F=qvB=mv^{2}\div r$$

The Attempt at a Solution

I calculated the period of the particle in the field as:

$$T= 2 \pi m\div qB$$

I don't know if this is what they want or if there's a way to calculate the total time.

 

[Shooting Star]

A delayed reply, but this one looks like just what you had asked.

http://regentsprep.org/Regents/physics/phys03/cdeflecte/default.htm

 

[Astronuc]

A charged particle will spend 1/2 period in a magnetic field (assuming it's constant) when it enters at the boundary from a region without the magnetic field.