A ball is dropped from a height of 20 meters. At what helght does the ball have a velocity of 10 meters/second?

Stars x and y are both bluish main sequence stars. star x has a higher absolute brightness than star y. how do the two stars compare? explain

In this thread, i would like you to comment on the nature of light and how operation of telescopes. light has a duality of a particle and a wave; which one affects your life? also how does light interact with optics inside telescopic systems? answer these questions in two paragraphs. then respond the another students response.

Aspacecraft that renters the earth’s atmosphere drastically slows down. the amount of kinetic energy the spacecraft has as it reenters the earths atmosphere