Week 11 Homework Assignment

 

  1. (P.398 Prob.2) The intensity of the sound wave from a jet airplane is 9.2W/m2 at a distance of  120m. What is the intensity of the sound wave that reaches the ground when the airplane flies overhead at an altitude of 8.6km? Assume that the sound wave radiates from the airplane equally in all directions.
  2. (P.398 Prob.6) What is the position of the peak of the pulse shown in Fig.11.24 at t =3.00s? (b) When does the peak of the pulse arrive at x = 4.00m?
  3. (P.399 Prob.12) What is the frequency of a wave whose speed and wavelength are 120m/s and 30.0cm, respectively?
  4. (P.P.399 Prob.18) Write an equation for a sine wave with amplitude 0.120m, wavelength 0.300m, and wave speed 6.40m/s traveling in the -x-direction.
  5. (p.399 Prob.22) Fig.11.26 shows a sine wave traveling to the right on a cord. The lighter line represents the shape of the cord at time t =0; the darker line represents the shape of the cord at time t = 0.10s. (Note that the horizontal and vertical scales are different,  What are (a) the amplitude and (b) the wavelength of the wave? (c) What is the speed of the wave? What are (d) the frequency and (e) the period of the wave?
  6. (P.400 Prob.28) Two traveling sine waves, identical except for a phase difference f, add so that their superposition produces another traveling wave with the same amplitude as the two component saves. What is the phase difference between the two waves?
  7. (P.400 Prob.30) Light of wavelength 0.500mm (in air) enters the water in a swimming pool. The speed of light in water is 0.750 times the speed in air. What is the wavelength of  the light in water?
  8. (P.400 Prob.36) A sound wave with intensity 25mW/m2 interferes constructively with a sound wave with intensity 15mW/m2. What is the intensity of the superposition of the two?
  9. (P.401 Prob.440 A cord of length 1.5m is fixed at both ends. Its mass per unit length is 1.2g/m and the tension is 12N. (a) What is the frequency of the fundamental oscillaation? (b) Whaat tension is required if the n = 3 mode has a frequency of 0.50kHz?