Assignment #1

Assignment #1 will be due on Tuesday, October 5th in class.

Exercises come from the end of each chapter in the area titled "Exercises." Specific exercises are labeled after the chapter title so that, for example, Exercise 1.3 refers to the third exercise from Chapter 1.

For this week only, the specific Exercises are copied from the book below.

Please write out your work to insure that can you get credit if you make a partial mistake when preparing your answers.

1.2 The speed of a bicycle increases from 5 mi/h to 10 mi/h in the same time that a car increases its speed from 50 mi/h to 55 mi/h. Compare their accelerations.

1.6 An object weighing 1 lb (English units) has a mass of 0.455 kg. Express its weight in newtons and thereby express a conversion factor for pounds to newtons.

2.4 A bass-reflex loudspeaker enclosure (see Fig. 19.16) is essentially a Helmholtz resonator. Given the following parameters, what resonance frequency might be expected. V = 0.5 m^3, a = 0.02 m^2, l = 0.05 m, speed of sound v = 343 m/s at T = 20˚C.

2.6 In the two-mass system shown in Fig 2.7, each mass is 2 kg and each spring constant K = 100 N/m. Calculate the frequencies of modes (a) and (b).

3.2 Two trumpet players tune their instruments to exactly 440Hz. Find the difference in the apparent frequencies due to the Doppler effect if one plays his or her instrument while marching away from an observer and the other plays while marching toward the observer. Is this enough to make them sound out of tune? (Assume 1 m/s as a reasonable speed.)


3.4 At what frequency does the wavelength of sound equal the diameter of the following (1 in. = 0.0254 m)
(a) a 15-in. woofer
(b) a 3-in. tweeter

4.6 A nylon guitar string 65 cm long has a mass of 8.3 * 10^-4 kg/m and the tension is 56 N. Find the frequencies of the first four partials.