SmartLearner

(Click the question to get the answer.)

1. What is meant by the term "frequency" of a sound wave?

This is the number of vibrations that occur per second.
Listen 1

2. What is the symbol and unit for frequency??

The symbol for frequency is f.
The unit for frequency is hertz or Hz.
Listen 2

3. What is meant by the wavelength of a wave?

This is the distance between two consecutive points in phase.
(It is the actual length of the wave before it repeats itself.)
Listen 3

4. What is the symbol and unit for wavelength?

The symbol for wavelength is the Greek letter λ.
The unit for wavelength is m (meters).
Listen 4

5. Write down the simple wave equation.

v = fλ
Listen 5

6. The wavelength of a sound wave is 0,85m, and its frequency is 400Hz.
Calculate its speed v.

v = fλ
v = (400)(0,85)
v = 340m.s^-1
Listen 6

7. Are sound waves "longitudinal" or "transverse"?

Longitudinal
The direction of vibrations and the direction of the movement are in the same direction.
Listen 7

8. What is meant by the period T of a wave, and how is it calculated?

This is the duration of a single wave, measured in s (seconds)
This is the time for which a single wave existed.

T = ¹/_f

9. The frequency of a wave is 400Hz. Calculate its period T?

T = ¹/_f
T = ¹/₄₀₀
T = 0,0025 s
T = 2,5 x 10^-3 s
Listen 9

10. The speed of a sound wave is 340m.s^-1, the period is 2 x 10^-3 s. Calculate its wavelength λ.

Calculate the frequency.
T = ¹/_f
2 x 10^-3 = ¹/_f
f = 500Hz

Since
v = fλ
340 = 500λ
λ = 0,68 m