A student creates a model of a sound wave coming from an object that is moving toward an observer to demonstrate the Doppler effect. Observer
- MED)
Using the model, which statement best describes the changes in the sound wave as it approaches the observer?
A The wavelength becomes longer and the pitch becomes lower.
OB The wavelength becomes longer and the pitch becomes higher.
C. The wavelength becomes shorter and the pitch becomes lower,
D. The wavelength becomes shorter and the pitch becomes higher

Asample of a gaseous substance changes into a liquid

Which is a substance that can be separated by physical means and is not the same throughout

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?