Energy inside a cyclotron, and the frequency of circular motion

[Parad0x88]

Homework Statement

One of the first cyclotrons, built in 1932, has D-s with a diameter of 28 cm, and its magnet was capable of producing magnetic field of 1.4 T. What is the maximal energy of the protons accelerated by this cyclotron? What is the frequency of the circular motion?

Homework Equations

A) E_k = (q²B²R²)/2m
B) ω = V / r, or qB / m

The Attempt at a Solution

A) ((1.602 X 10^-19)² X 1.4²T X 0.28²m)/(2 X 1.673 X 10^-27kg) = 1.1786 X 10^-12 J

B) (1.602 X 10^-19 X 1.4T) / 1.673 X 10^-27kg = 1.34059 X 10⁸ rad/s

That make sense to your guys?

 

[gneill]

Shouldn't the radius be half of the diameter?

 

[Parad0x88]

Shouldn't the radius be half of the diameter?

Oh you're right! Read the problem too fast there!