An electric current is produced by which of the following processes? electrical resistance transfer of protons convection currents electromagnetic induction

Physics make-up packetname_cle14. an observer hears a sound with a frequency of 400 hz. if the speed of sound is 340 m/s,what is the wavelength of the sound? a. 0.85 mb. 1.2 mc. 2.75 m13.6 m15. as sound travels from steel into air, its speed decreases. if the frequency of the wavedoesn't change, what happens to its wavelength? a. it increases(b) it decreasesc. it remains the samed. there is not enough information given

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

Astone is thrown into a pond. what happens to the amplitude of the resulting waves as they get farther from the point where the stone hit the water? explain.