Showing 171 to 180 of 618 Questions
  • Use information from Table 16.2 to answer the following questions about sound in air. At 20oC the bulk modulus for air is 1.42 X 105 Pa and its density is 1.20 kg/m3. At this temperature, what are the pressure amplitude fm Pa and atm) and the displacement amplitude (in m and run) (a) For the softest sound a person can normally hear at 100

  • Longitudinal Waves in Different Fluids. (a) A longitudinal wave propagating in a water-filled pipe has intensity 3.00 X 10-6w/m2 and frequency 3400 Hz. Find the amplitude A and wavelength A of the wave. Water has density 1000 kg/m3 and bulk modulus 2.18 X 105 Pa. (b) If the pipe is filled with air at pressure 1.00 X 105 Pa and density 1.2

  • Derive Eq. (16.14) from the equations that precede it.

  • A sound wave in air at 20°C has a frequency of 150 Hz and displacement amplitude of 5.00 X 10-3 mm. For this sound wave calculate the (a) Pressure amplitude (in Pa); (b) Intensity fm W/m2); (c) Sound intensity level fm decibels).

  • What is the sound intensity level in a car when the sound intensity is 0.500 µw/m2? What is the sound intensity level in the air near a jackhammer when the pressure amplitude of the sound is 0.150 Pa and the temperature is 20.0°C?

  • For a person with normal hearing, the faintest sound that can be heard at a frequency of 400 Hz has a pressure amplitude of about 6.0 X 10-5 Pa. Calculate the (a) Intensity; (b) Sound intensity level; (c) Displacement amplitude of this sound wave at 20oC.

  • The intensity due to a number of independent sound sources is the sum of the individual intensities. (a) When four quadruplets cry simultaneously, how many decibels greater is the sound intensity level than when a single one cries? (b) To increase the sound intensity level again by the same number of decibels as in part (a) how many more

  • A baby's mouth is 30 cm from her father's ear and 1.50 m from her mother's ear. What is the difference between the sound intensity levels heard by the father and by the mother?

  • The Sacramento City Council recently adopted a law to reduce the allowed sound intensity level of the much despised leaf blowers from their current level of about 95 dB to 70 dB. With the new law, what is the ratio of the new allowed intensity to the previously allowed intensity?

  • (a) By what factor must the sound intensity be increased to raise the sound intensity level by 13.0 dB? (b) Explain why you don't need to know the original sound intensity.