Two identical metal spheres a and b are in contact. both are initially neutral. 1.0× 10 12 electrons are added to sphere a, then the two spheres are separated. part a afterward, what is the charge of sphere a? express your answer with the appropriate units. q a q a = nothing nothing submitrequest answer part b afterward, what is the charge of sphere b? express your answer with the appropriate units. q b q b = nothing nothing submitrequest answer provide feedback next

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?