Protons are accelerated in a cyclotron so that the maximum
curvature radius of their trajectory is equal to r = 50 cm. Find:
(a) the kinetic energy of the protons when the acceleration is
completed if the magnetic induction in the cyclotron is B = 1.0 T;
(b) the minimum frequency of the cyclotron's oscillator at which
the kinetic energy of the protons amounts to T = 20 MeV by the
end of acceleration.