He Two carts with masses of 1.5 kg and 0.75 kg, respectively, are held together by a compressed spring. When released, the 1.5 kg cart moves to the left with a velocity of 3.4 m/s. What is the velocity of the 0.75 kg cart? (Disregard the mass of the spring.)

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

Clothes dryer uses about 7 amps of current from a 240 volt line. how much power does it use?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?