As an airplane rises through the atmosphere, machines cause the pressure inside the cabin to decrease. Based on your observations from the Can Crush Lab, why is this change in pressure necessary? Air pressure inside the plane should match the air pressure outside the plane.
Air pressure inside the plane should be less than the air pressure outside the plane.
Air pressure outside the plane should be less than the air pressure inside the plane.
Air pressure outside the plane should be more than the air pressure inside the plane.

Comedians like to joke that the reason we haven’t been visited by intelligent life from elsewhere in the universe is that aliens have been monitoring earth’s broadcasts of intellectually embarrassing tv programs, like gilligan’s island, fear factor, the jersey shore, and the jerry springer showand so consider us far too primitive to merit a visit. let’s check the assertion that aliens could have been receiving them. tv programs are broadcast at a frequency of about 100mhz with about 100kw of total power in 30frames per second, which emanatesroughly uniformly in all directions. assume that interstellar space transmits these broadcasts without attenuation. no matter how smart they are, aliens would require at least one photon per frame to interpret our signals. findthe number of photons per unit time per unit area reaching a receiver on a possible planet in the nearest star system, which is about 4 light-years away (a light-year is the distance light travels in a year). if aliens aimed a receiver or detector directly at earth, how big (in diameter) would it have to be to receive a photon per frame

He viscosities of several liquids are being compared. all the liquids are poured down a slope with equal path lengths. the liquid with the highest viscosity will

What happens when a rubber rod is rubbed with a piece of fur?