Since Copernicus did not have satellite pictures , what did he most likely use to make another scientist believe his explanation about the solar system

An electromagnet is a device in which moving electric chargers in a coil of wire create a magnet.whats one advantage of using electromagnetic in devices

Distinguish between linear momentum and angular momentum

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?