Choose all the answers that apply.

Stars:

are classified by temperature and color
are made mostly of hydrogen and helium
orbit the sun
are mostly found between Mars and Jupiter
generate their own heat and light

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?

Name three different units of energy used to measure heat and describe what type of situations each is usually used.

Explain earth's motion, using the terms "precession" and "rotation" in your answer.