Sound Waves Quiz

The following information applies to questions 1 to 4. The diagram below is from two different sound waves (A and B) as shown in the figure below. The graphs describe the changes in air pressure over time.

What is the ratio of the amplitudes A:B

• 1:1

• 5:8

• 8:5

• 1:4

What is the ratio of the frequencies A:B?

• 1:1

• 2:1

• 1:2

• 1:4

Which of the two sound graphs depicts a higher pitch? Justify your answer.

Which of the two sound graphs has a higher volume? Justify your answer.

Sound waves are longitudinal waves with areas of higher and lower pressure. Which one (or more) of the following statements is true?

• Pressure variation is at a maximum at a rarefaction.

• Pressure variation is at a minimum at a rarefaction.

• Pressure variation is at minimum at a compression

• Pressure variation is zero at a rarefaction and a maximum at a compression.

The following information relates to questions 6 to 8. The diagram shows the displacement of the sound wave as a function of distance from the source. The sound wave is traveling to the right at a particular time. The wave is travelling at 340m s^-1 . What is the amplitude of the sound wave?

• 1.0

• 2.0

• 4.0

• 40

What is the wavelength of the sound wave?

• 2.0m

• 3.0m

• 4.0m

• 5.0m

In what direction is a particle at point Y moving?

• Up

• Down

• Left

• Right

Which one or more of the following sound wave properties are NOT dependent on the source producing the sound?

• Intensity

• Frequency

• Speed

• Volume

in a car race, a race car is travelling down a straight section of road towards you at a speed of 180 km/h. The engine noise may be considered to have a constant frequency of 2000Hz. The speed of sound is 340 m s-¹. If you remain stationary:

a) what frequency does the engine sound have as the car approaches you?

b) frequency does the engine sound have as the car travels away from you?