The formulas for distance traveled for two electronically controlled cars are given by: E(t)=20t−2t2 and F(t)=t2+5t, where distance is in feet and time is in minutes. a.) Find the longest interval, beginning at t=0, over which the E-car is traveling faster than the F-car. from t=0 to t=2.5 2.5b.) The average trip speed at time t of the E-car is defined to be E(t)/t (total distance traveled over total time elapsed at time t). Find the positive time t at which the average trip speed and the instantaneous speed of the E-car are the same. If no such time exists, enter NONE. t=NONE NONEc.) Find the time at which the E-car is traveling 3 ft/min faster than the F-car.

What is work? how much work is done to move an object 0 meters?

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

What are the north and south poles of a solenoid change with?