Ch 14 Sec 3 Check Your Understanding

What is the Doppler effect?

• The Doppler effect is a change in the observed speed of a sound due to the relative motion between the source and the observer.

• The Doppler effect is a change in the observed frequency of a sound due to the relative motion between the source and the observer.

• The Doppler effect is a change in the observed intensity of a sound due to the relative motion between the source and the observer.

• The Doppler effect is a change in the observed timbre of a sound, due to the relative motion between the source and the observer.

Give an example of the Doppler effect caused by motion of the source.

• The sound of a vehicle horn shifts from low-pitch to high-pitch as we move towards it.

• The sound of a vehicle horn shifts from low-pitch to high-pitch as we move away from it.

• The sound of a vehicle horn shifts from low-pitch to high-pitch as it passes by.

• The sound of a vehicle horn shifts from high-pitch to low-pitch as it passes by.

What is a sonic boom?

• It is a destructive interference of sound created by an object moving faster than sound.

• It is a constructive interference of sound created by an object moving faster than sound.

• It is a destructive interference of sound created by an object moving slower than sound.

• It is a constructive interference of sound created by an object moving slower than sound.

What is the relation between speed of source and value of observed frequency when the source is moving towards the observer?

• They are independent of each other.

• The greater the speed, the greater the value of observed frequency.

• The greater the speed, the smaller the value of observed frequency.

• The speed of the sound is directly proportional to the square of the frequency observed.