Part A A harvest mouse can detect sounds as quiet as -10 dB. Suppose you are sitting in a field on a very quiet day while a harvest mouse sits nearby. A very gentle breeze causes a leaf 1.7 m from your head to rustle, generating a faint sound right at the limit of your ability to hear it. The sound of the rustling leaf is also right at the threshold of hearing of the harvest mouse. How far is the harvest mouse from the leaf? Express your answer with the appropriate units. μΑ d = Value

A loudspeaker, mounted on a tall pole, is engineered to emit 75% of its sound energy into the forward hemisphere, 25% toward the back. You measure an 85 dB sound intensity level when standing 1.0 m in front of and 2.5 m below the speaker. Part A What is the speaker's power output? Express your answer with the appropriate units. ► View Available Hint(s)

A train whistle is heard at 250 Hz as the train approaches town. The train cuts its speed in half as it nears the station, and the sound of the whistle is then 240 Hz. Part A What is the speed of the train before slowing down? Express your answer to two significant figures and include the appropriate units. V1 = Part B Value v2 = What is the speed of the train after slowing down? Express your answer to two significant figures and include the appropriate units. LO μA Units Value ? Units ?

An open organ pipe (i.e., a pipe open at both ends) of length Lo has a fundamental frequency fo. Part A If the organ pipe is cut in half, what is the new fundamental frequency? ► View Available Hint(s) 4 fo 2 fo fo fo/2 fo/4

Two loudspeakers emit identical sound waves along the x-axis. The sound at a point on the axis has maximum intensity when the speakers are 22 cm apart. The sound intensity decreases as the distance between the speakers is increased, reaching zero at a separation of 33 cm. Part A What is the wavelength of the sound? Part B If the distance between the speakers continues to increase, at what separation will the sound intensity again be a maximum?

During takeoff, the sound intensity level of a jet engine is 170 dB at a distance of 24 m. Part A What is the sound intensity level at a distance of 1.0 km? Express your answer to two significant figures and include the appropriate units. B = Submit Value Units Previous Answers Request Answer ?

Part A The ability to hear a "pin drop" is the sign of sensitive hearing. Suppose a 0.48 g pin is dropped from a height of 29 cm, and that the pin emits sound for 1.3 s when it lands. Assuming all of the mechanical energy of the pin is converted to sound energy, and that the sound radiates uniformly in all directions, find the maximum distance from which a person can hear the pin drop. (This is the ideal maximum distance, but atmospheric absorption and other factors will make the actual maximum distance considerably smaller.) Express your answer using two significant figures. km

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