When a sound source is moving toward the observer, the observer will hear a higher pitch due to the change to a lower frequency. higher pitch due to the change to a higher frequency. lower pitch due to the change to a higher frequency. lower pitch due to the change to a lower frequency.

you will hear a higher pitch due to a higher frequency.

The right option is higher pitch due to change to a higher frequency

Explanation:

Pitch can be defined as the characteristics of a note which enables us to differentiate a high note from a low one.

Frequency: this is the number of oscillation per seconds expressed in Hertz (Hz)

Pitch of a note depends on frequency of a sound wave

I.e as the frequency become high, The higher will be the pitch.

From the question above, when the sound source is moving towards the observer,

Let the frequency of the sound source = f

Let the apparent frequency (frequency which the observer will hear) = f¹

Let the velocity of the source sound = Vₓ

Let the velocity of the observer = V

∴ The apparent frequency (f¹) when the source sound is moving towards the observer = {V/(V-Vₓ)}f

f¹ = {V/(V-Vₓ)}f

since (V-Vₓ ) is less than V, therefore f¹ will be increased.

If f¹ is increased, the pitch is also increased.

The right option is higher pitch due to change to a higher frequency