What is the shortest time that a jet pilot starting from rest can take to reach Mach-3.80 (3.80 times the speed of sound) without graying out

Astudent wears sunglasses to her read a book more easily which wave interaction occurs as light passes from the air into the plastic lenses? a polarization b. refraction c. diffraction d. interference

Hydrogen and helium are both members of?

By what primary heat transfer mechanism does the sun warm the earth?