25. Which of the following samples of metals will displace the greatest volume of water (hint: solve for the 3 volumes)?
Sample 1 is 25 g of aluminum which has a density of 2.70 g/cm3.
Sample 2 is 45 g of gold which has a density of 19.3 g/cm3.
Sample 3 is 75 g of lead which has a density of 11.3 g/cm3.
aluminium
gold
lead
none of the above

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.