A measurement of the circumference of a disk has an uncertainty of 1.5 mm. how many measurements must be made'

Because light travels in a straight line and casts a shadow, isaac newton hypothesized that light is

The force needed to overcome static friction is usually less than that needed to overcome kinetic friction.true or false?

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?