Properties of Waves Flashcards
What happens when a source emits a wave?
Several waves are emitted that travel in the same direction, not just one individual wave.
What is a wavefront?
A wavefront is an imaginary line drawn across the peaks of different waves.
How is the next wavefront drawn?
The next wavefront is drawn at the next peak of the wave.
What is the distance between each wavefront equal to?
The distance between each wavefront is equal to one wavelength.
How are wavefronts represented in the Doppler Effect diagram?
In the Doppler Effect diagram, the wavefronts are represented as black circles.
What is the Doppler Effect?
The Doppler Effect occurs when a wave is emitted from a moving source and causes the frequency of the wave to appear to change as the source moves past you.
How do we experience the Doppler Effect?
We experience the Doppler Effect when an ambulance or police car with its siren blaring passes us and the pitch sounds higher as it approaches and lower as it moves away.
Why do sound waves change frequency in the Doppler Effect?
The sound waves have a constant wave speed. As the source moves it approaches the sound waves ahead shortening the wavelength and spreads them out behind lengthening the wavelength.
How do the wavefronts change in the Doppler Effect?
The wavefronts ahead of the moving source become closer together shortening the wavelength while the wavefronts behind become more spread out lengthening the wavelength.
What causes the change in frequency in the Doppler Effect?
The change in wavelength causes a change in frequency. If the wavelength decreases but the wave speed stays the same then the frequency must increase.
What equation relates speed frequency and wavelength?
The equation is speed = frequency x wavelength.
What happens during reflection of a wave?
Reflection occurs when waves bounce off a surface.
What happens during refraction of a wave?
Refraction occurs when wave speed changes as a wave travels through a different material.
