Question

a band director instructs students to play a pitch louder. how will the sound wave change when the band plays the same pitch louder?
the speed of the sound wave will increase.
the frequency of the sound wave will increase.
the wavelength of the sound wave will increase.
the amplitude of the sound wave will increase.

Explanation:

The speed of a sound wave depends on the medium (e.g., air, water). Since the medium doesn't change when playing louder, speed won't increase. Frequency determines pitch. As the pitch is the same, frequency remains unchanged. Wavelength is related to frequency ($v = f\lambda$, where $v$ is speed, $f$ is frequency, $\lambda$ is wavelength). With $v$ (medium - related) and $f$ (pitch - related) unchanged, wavelength $\lambda$ also doesn't change. Amplitude is related to the loudness of a sound wave. Louder sound means greater amplitude.

Answer:

The amplitude of the sound wave will increase.