Solving Cyclotron Movement Problem with 500V and 0.790B

[Canadian]

Homework Statement

A 61.0 cm diameter cyclotron uses a 500 V oscillating potential difference between the dees. The magnetic field strength is 0.790 ?

How many revolutions would a proton make before leaving the cyclotron?

Homework Equations

v/r=Bq/m Ke=1/2mv^2

The Attempt at a Solution

I am completely stumped on this problem, I have calculated the max speed, and therefor max kinetic energy. But cannot figure out how to derive number of revolutions from there.

Any hints would be greatly appreciated.

Thanks

 

[lalbatros]

Canadian,

Why would the electron leave the cyclotron,
Describe first how this device works.
How does the electron reach the escape speed?

Michel