A flat metal washer (a circular plate with a circular hole cut out of it) is heated. Does the hole get smaller, larger, or remain the same size? Explain.

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?