Aseries of dominos are stood on end close together so that when one domino is tipped over it will set off a chain reaction of collisions knocking over all the other dominos. which describes the state of each domino before any are knocked over? a. unstable equilibrium b. unstable and not in equilibrium c. stable, but not in equilibrium d. stable equilibrium

Two loudspeakers, 5.5 m apart and facing each other, play identical sounds of the same frequency. you stand halfway between them, where there is a maximum of sound intensity. moving from this point toward one of the speakers, you encounter a minimum of sound intensity when you have moved 0.33 m . assume the speed of sound is 340 m/s.part a) what is the frequency of the sound? part b) if the frequency is then increased while you remain 0.21 m from the center, what is the first frequency for which that location will be a maximum of sound intensity? express your answer to two significant figures and include the appropriate units.