What force decreases as air rises that allows it to expand?

How does convection affect our atmosphere? our layers of earth? our oceans?

The place you get your hair cut has two nearly parallel mirrors 6.00 m apart. as you sit in the chair, your head is 2.00 m from the nearer mirror. looking toward this mirror, you first see your face and then, farther away, the back of your head. (the mirrors need to be slightly nonparallel for you to be able to see the back of your head, but you can treat them as parallel in this problem.) how far away does the back of your head appear to be?

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f