[CM.06] A volcanic eruption takes place in a location. Lava flows down the volcano into human habitation. It blocks the flow of a river and makes it change its path. Which Earth systems interact during this process?
geosphere, atmosphere, and biosphere
hydrosphere, geosphere, and biosphere
atmosphere, geosphere, and cryosphere
biosphere, cryosphere, and hydrosphere

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.