Sound with a frequency of 1250 hz leaves a room through a doorway with a width of 1.05 m. at what minimum angle relative to the centerline perpendicular to the doorway will someone outside the room hear no sound? use 344 m/s for the speed of sound in air and assume that the source and listener are both far enough from the doorway for fraunhofer diffraction to apply. you can ignore effects of reflections. theta = ? degrees, ? degrees, ? degrees (should be three terms)

Calculate the ratio of h+ ions to oh– ions at a ph = 6. find the concentration of h+ ions to oh– ions listed in table b of your student guide. then divide the h+ concentration by the oh– concentration. record this calculated ratio in table a of your student guide. compare your approximated and calculated ratios of h+ ions to oh– ions at a ph = 6. are they the same? why or why not? record your explanation in table a. what is the concentration of h+ ions at a ph = 6? mol/l what is the concentration of oh– ions at a ph = 6? mol/l what is the ratio of h+ ions to oh– ions at a ph = 6? : 1

What is the major limitation to the light microscope?

Panel bc in fig. p2.76 is semi-circular, with the 3 meter radius and horizontal straight edge through point b. compute (a) the hydrostatic force of the water on the panel, (b) its center of pressure, and (c) the moment of this force about point b. assume atmospheric pressure on the dry side of the panel