Consider the following five kinds of objects: open cluster, giant molecular cloud, globular cluster, group of o and b stars, and planetary nebulae.
which occur only in spiral arms?
which occur only in the parts of the galaxy other than the spiral arms?
which are thought to be very young?
which are thought to be very old?
which have the hottest stars?

Suppose water is leaking from a tank through a circular hole of area ah at its bottom. when water leaks through a hole, friction and contraction of the stream near the hole reduce the volume of water leaving the tank per second to cah 2gh , where c (0 < c < 1) is an empirical constant. a tank in the form of a right-circular cone standing on end, vertex down, is leaking water through a circular hole in its bottom. (assume the removed apex of the cone is of negligible height and volume.) (a) suppose the tank is 20 feet high and has radius 8 feet and the circular hole has radius 2 inches. the differential equation governing the height h in feet of water leaking from a tank after t seconds is dh dt = − 5 6h3/2 . if the height of the water is initially 8 feet, how long will it take the tank to empty? (round your answer to two decimal places.)

1.what is where an object is located 2. what is how fast an objects speed is changing 3. what is how fast an object is moving

What is a possible result of higher air temperature caused by global warming