You lift a 44 N box from the floor and place it on a shelf that is 1.5 m above the ground . How much work did you use in lifting the box ?

An object is located 30.0 cm from a concave mirror. the focal length is 15.0 c,. what is the image distance? a. 30.0 cm b. -10 cm c. 10.0 cm d. -30.0 cm

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

Choose the correct general statement concerning the total potential and kinetic energy at any point along the arc of swing. the total energy at any point along the arc of swing of the pendulum is always less than 12 joules. the total energy at any point along the arc of swing of the pendulum is always more than 12 joules. the total energy at any point along the arc of swing of the pendulum is always equal to 12 joules. not enough information to determine