Aeight conducting lops wrap around a sphere, with a 40.0 cm radius and a 1.20 kg mass. this sphere rests on a 30 degree inclined plane which experiences a 0.600 t magnetic field, pointing directly up. current that flows through these loops provide a torque that keeps the sphere from rolling down this plane.

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 5 mev to 20 mev. this ion has a mass very close to that of a proton because the electron mass is negligible—about 1 2000 of the proton’s mass. a typical magnetic field in such cyclotrons is 1.9 t. (a) what is the speed of a 5.0-mev h-? (b) if the h- has energy 5.0 mev and b = 1.9 t, what is the radius of this ion’s circular orbit?