30 .
Next-Tone QUESTION
5).
A spool rolls on a horizontal table, approaching a horizontal
bar whose top is at the same height as the bottom of the spool's
axle. After the larger disks of the spool leave the table and the
axle rolls along the bar, the spool's translational speed
BAR
TABLE

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?