An observer notes that the pitch of a sound is becoming progressively higher. the observer can conclude that the sound is moving

Avehicle has an oil leak that is causing the entire oil pan to be wet, but inspection reveals no exact source after cleaning off the oil residue. technician a says to install a fluorescent dye in the crankcase and operate the engine, then re-inspect for leaks with a special light (black light). technician b says the oil leak may be coming from a source at the top of the engine, such as a valve cover gasket. who is correct?

Do you agree with scientist’s prediction about the warming of alaska and other polar regions?

Photons with the highest energy have the longest period