Jorge has made the hypothesis that the more he feeds a mouse, the shinier its fur will be, because the mouse will be healthier.
what should be the independent variable in an experiment testing this hypothesis?

a. how shiny each mouse's fur is
b. how much each mouse weighs
c. the type of food he feeds each mouse
d. the amount of food he feeds each mouse

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?