Lizard: A lizard is running in a straight line according to the following: xx(tt) = tt3⁄3 − tt2 + tt He starts at tt = 0. (a) Determine vv(tt). (b) When is the lizard at rest? (c) When is the lizard moving in the positive xx direction? (d) When is the lizard moving in the negative xx direction? (e) When does the lizard have zero acceleration?

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.