Calculating Proton Speed in 0.1T Magnetic Field

[jbuck886]

Homework Statement

A magnetic field of 0.1T forces a proton beam of 1.5mA to move in a circle of radius 0.1m. The plane of the circle is perpendicular to the magnetic field. What is the speed of the proton in the beam as it moves in the circle.

Homework Equations

The Attempt at a Solution

Not sure where to start

 

[Doc Al]

How do you find the magnetic force on a moving charge? If something moves in a circle, what's it's acceleration?

 

[jbuck886]

A= v2/r
I think

 

[Doc Al]

A= v2/r
I think

Good. Find an expression for the magnetic force and apply Newton's 2nd law.