The unit of area is called derived unit, why?

An asteroid is discovered in a nearly circular orbit around the sun, with an orbital radius that is 2.47 times earth's. what is the asteroid's orbital period, its "year," in terms of earth years?

If steel is more dense that lake water, why can a boat float

Choose a synonym for the underlined homonym (a word with two or more meanings). i did not expect the boat to rock so much. a. boulder c. astound b. sway d. shock