A cyclotron with dee radius 45.9 cm is operated at an oscillator frequency of 12.9 MHz to accelerate protons. (a) What magnitude B of magnetic field is required to achieve resonance? (b) At that field magnitude, what is the kinetic energy of a proton emerging from the cyclotron? Suppose, instead, that B= 1.49T. (c) What oscillator frequency is required to achieve resonance now? (d) At that frequency, what is the kinetic energy of and emerging proton?