Chapter 18, Problem 111A

To determine

The sound of a car horn to the pedestrian as the car brakes to allow him to cross the street.

Explanation of Solution

Introduction:

Pitch is the sensation of a sound frequency.Pitch of the sound is used to decide the sound is higher or lower.

When car speed is high, the sound of horn heard by pedestrian is high. Since car velocity is added in sounds velocity of horn. As the car slows down the pitch of thehorn heard by pedestrian will decrease since sound heard.

Conclusion:

Pitch of sound decrease.