To a bystander, which property of a sound wave changes due to the doppler a. speed b. phase c. amplitude d. frequency

Adeuteron, 21h, is the nucleus of a hydrogen isotope and consists of one proton and one neutron. the plasma of deuterons in a nuclear fusion reactor must be heated to about 3.02×108 k . what is the rms speed of the deuterons? express your answer using two significant figures.

Oil rich countries in the middle east cover about 4% of earths total land area but prossess about 48% of the worlds known oil reserves what is the main reason for high concentration of reserves in this part of the world

The half-life of a certain element is 100 days. how many half-lives will it be before only one eighth of this elementremains?