Why are SI units used so often in science?

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?

Write the correct abbreviation for each metric unit

1. how to locate the image in converging(concave) mirror and diverging (convex) mirror with salt. 2. how to locate the image in a converging (convex) lens and diverging (concave) lens with salt.