Atruck is traveling 70.0 kph away from you. the driver is blowing the horn, which has a frequency of 400 hz. the air temperature is 25°c. what is the observed frequency of the horn?

In a system, when potential energy decreases, then entropy also decreases. true false

While standing outdoors one evening, you are exposed to the following four types of electromagnetic radiation: yellow light from a sodium street lamp, radio waves from an am radio station, radio waves from an fm radio station, and microwaves from an antenna of a communications system. rank these type of waves in terms of increasing photon energy.

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2