Two spheres have charges -3.1 x 10^-7 C and -3.7 x 10^-7 C, respectively. They are separated by a distance of 9.0 cm. Calculate the magnitude of the force the two charges exert on each other?

The largest observatory complex in the world is on mauna kea, the tallest mountain on earth. what are some factors astronomers consider when selecting an observatory site? don’t forget practical ones. should astronomers, for example, consider building an observatory on denali (mount mckinley) or mount everest?