Standing on the Sidewalk We Listen to the Sound of the Horn

question 39

Multiple Choice

Standing on the sidewalk we listen to the sound of the horn of a passing car.As the car passes us,the frequency of the sound changes from high to low in a continuous manner,that is,there is no abrupt change in the frequency heard.This is because

• A)the pitch of the sound of horn changes continuously.
• B)the intensity of the sound heard changes continuously.
• C)we are not standing directly in the path of the traveling car.
• D)All of the reasons contribute to the heard effect.