Question

5. Circle the letter of the correct answer. How is wavelength determined
for a longitudinal wave?
a. Measure the distance between adjacent rarefactions.
b. Measure the distance between adjacent crests.
c. Measure the distance between adjacent troughs.
Wave Speed (pages 505–506)
6. Write a formula you can use to determine the speed of a wave.
7. Is the following sentence true or false? The speed of a wave equals
its wavelength divided by its period.
8. Circle the letter of the sentence that tells how wavelength is related to
frequency for a wave traveling at a constant speed.
a. Wavelength is directly proportional to frequency.
b. Wavelength is inversely proportional to frequency.
c. A wave with a higher frequency will have a longer wavelength.
Amplitude (page 507)
9. What is the amplitude of a wave?

Answer 1

5. a. Measure the distance between adjacent rarefactions. (For a longitudinal wave you can measure between adjacent compressions or adjacent rarefactions — both give one wavelength.)

6. v = f·λ (equivalently v = λ / T, since f = 1/T)

7. True. v = λ / T is equivalent to v = f·λ because f = 1/T.

8. b. Wavelength is inversely proportional to frequency. (At constant speed λ = v / f.)

9. Amplitude is the maximum displacement of the medium from its equilibrium position (for transverse waves: distance from equilibrium to a crest or trough; for longitudinal waves: the maximum compression or rarefaction).