S302, Kewley-Port 9/14/07

Homework 4
WAVEFORMS DIMENSIONS AND PHASE

 

1. Convert the following to radians: 30º, 80º, 135º. ______________, ______________, _______________

2. Convert the following to degrees: /4, 7 /8. ______________, __________________ . Change your calculator to the mode 'radians'. sin (/4) = ____________?   sin (7 /8) = _____________?

3. Consider the equation: y = sin (2 f t). For t = 0, 0.1, 0.2 and 0.3 seconds, and f = 300 Hz, calculate the values for y at each t. ______________, ______________, _______________

4. Consider the equation: y = A sin (2 pi f t + phi ). For t = 0, 0.1, 0.2 and 0.3 seconds, and A = 2, f = 300 Hz, phi = pi , calculate the values for y at each t. ______________, ______________, _______________

5. Explain what it means that one sine wave lags another by 90º. Draw a picture if you'd like.

6. Angular velocity = 3600 degrees/5 s. What is the frequency?

7. The speed 800 Hz tone traveling in air at room temperature is 340 m/s. a)  lambda =  __________? (b) Draw a waveform showing how the pressure waveform changes with distance. Mark one wavelength, on the graph.  (c) If the tone is traveling in water with a speed of 1360 m/s,  lambda =  __________?

8. On Fig. 2-22, look at the middle figure.
   a) Is it low or high damped?___________  Explain.   b) The amplitude of the first peak is .631, and the second peak is .545. Calculate the damping factor. _________