Transmission of Sound Flashcards

All 5 cards in this deck

What happens to the frequency of a sound wave when it passes from one medium into another?

It stays the same — the frequency is set by the source.

What happens to the speed and wavelength of a sound wave when it passes into a medium in which sound travels faster?
e.g. from air into water

The speed increases and, because the frequency is unchanged, the wavelength increases ($v = f\lambda$).

True or false? When a sound wave passes from air into water its frequency increases because it travels faster.

False. The frequency stays the same; the speed and wavelength both increase.

Why does a sound wave change direction (refract) when it crosses a boundary between two media at an angle?

Because the speed of sound is different in the new medium, so the wavelength changes and the wave bends.

True or false? Sound can travel through a vacuum.

False. Sound needs particles of a medium to vibrate, so it cannot travel through a vacuum.