Answers: 2
Physics, 22.06.2019 00:30
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
Answers: 2
Physics, 22.06.2019 15:30
Two pans of a balance are 24.1 cm apart. the fulcrum of the balance has been shifted 1.33 cm away from the center by a dishonest shopkeeper. by what percentage is the true weight of the goods being marked up by the shopkeeper? assume the balance has negligible mass. answer in units of %.
Answers: 1
Physics, 22.06.2019 16:20
What is the single most important equation in all of physics?
Answers: 1
Which describes a characteristic of metallic bonds? metal ions have the highest ability to attract...
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Physics, 19.05.2021 19:20
Biology, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Chemistry, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20
Mathematics, 19.05.2021 19:20