1) The intensity level of sound 200 m from a loud speaker at a heavy metal concert is 100 dB. At what distance from the speaker will the sound intensity level will be a tolerable 80 dB? Assume that thespeaker produce spherical sound wave.

2) While standing at a point
on the roadside shoulder, a police car chasing a speeder was approaching you. At that moment you hear the siren of the police car at a frequency of 560 kHz. When the police car passes, the frequency of the siren changes to 480 Hz. What was the speed of the police car if you assume that the speed of sound is 360 m/s?

3) You approach with a vibrating tuning fork above a resonating tube
(one end closed) that is filled with water at a certain level. The tuning fork resonates when a height of air column is 0.150 m and again0.450 m. What is the frequency of the fork when the speed of sound is taken to be 340 m/s?