A bystander hears a siren vary in frequency from 592 Hz to 396 Hz as a fire truck approaches, passes by, and moves away on a straight street. What is the speed of the truck?

What is the relationship between the wavelength of a wave and it's energy?

The us government wants to allocate billions of dollars in the next 10 years to assure our future energy security. the funds will be spread among a variety of possible energy resources. where do you think the government should put the greatest support: solar energy, wind energy, clean coal, oil exploration, gas exploration, or a combination of sources? are there other efforts that should be explored? support your position with cited information for both questions.

Asample of a gaseous substance changes into liquid. this process is called (blank) and it takes place when heat is (blank) a gaseous system