According to the doppler effect, the sound of a police car siren (a. quieter b. louder) (a. higher b. lower) pitched as it approaches the observer.

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.

The transfer of heat through the movement of a gas or liquid a. convection b. conduction c. radiation

1. a net force of 100 newton’s is applied to a wagon for 5 seconds. this causes the wagon to undergo a change in momentum of