Which of the following is true? a. air pressure at the top of mount everest is higher than at the bottom of the grand canyon. b. trace fossils contain actual physical remains of a dead organism, such as bone or teeth. c. coal and oil can slow decomposition of dead organisms, which is why deposits often contain fossils. d. the earth continuously makes new water to replace old water lost by evaporation, transpiration, and sublimation.

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

Transfer chemicals from one location to another to weather objects. a-water b-physical weathering c-chemical weathering

Afrequency generator sends a 550 hz sound wave through both water and ice. what is the difference in wavelength between the wave produced in ice and the wave produced in water?