Cyclotrons are widely used in nuclear medicine for producing short-lived radioactive isotopes. these cyclotrons typically accelerate h− (the hydride ion, which has one proton and two electrons) to an energy of 5mev to 20mev. this ion has a mass very close to that of a proton because the electron mass is negligible−about 1/2000 of the protons mass. a typical magnetic field in such cyclotrons is 1.7 t .

part a

what is the speed of a 5.0-mev h−?

express your answer with the appropriate units.

part b

if the h− has energy 5.0mev and b= 1.7 t , what is the radius of this ions circular orbit?

express your answer with the appropriate units.