A car speeds at 21.5 m/s. The force of resistance remains constant at 375 N during this time. What is the average power developed by the car’s engine?

Which of the statements about waves is true? a. in longitudinal waves, particles move perpendicular to the direction the wave is traveling.b. both transverse and longitudinal waves can travel through water c. electromagnetic waves are a type of longitudinal waves.d. in a transverse wave, particles move parallel to the direction the wave is traveling.

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

Acoil suspended freely, points in some direction when no current is passed through it . can you tell what will happen when a current is passed though it?