When a body moves in circular motion at constant speed a. the velocity and acceleration point in the same direction. b. the velocity and acceleration point in opposite directions. c. the velocity and acceleration point perpendicular to each other. d. the acceleration is zero. e. none of the above.

The difference between a red shift and a blue shift has to do with wavelength frequency. t or f

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.)

How is sound energy produced a. vibrating objects b. objects being heated c. temperature differences d. stationary objects