Why did the boy hear the pitch of the sound change? What does this tell us about the frequency sound? Support your conclusion based on results from from the experiment and your knowledge of sound waves

Due to the Doppler effect

Explanation:

This effect is called "Doppler effect".

It occurs when there is a source of a wave in relative motion with respect to an observer.

In this situation, there is a change in the apparent frequency of the sound, as observed by the observer. In particular, the apparent frequency is given by:

where

f is the real frequency of the wave

f' is the apparent frequency

v is the speed of the wave

is the velocity of the observer

is the velocity of the wave source

This phenomenon occurs, for instance, with sound waves; a daily example is when we hear the sound of the siren of an ambulance. We have 2 possible situations:

- When the ambulance is moving towards us, we hear an increase in the frequency of the sound

- When the ambulance is moving away from us, we hear a decrease in the frequency of the sound

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.