The bug in the center of the puddle is bobbing up and down. What is he producing? ______________.

Disturbances

The bug is staying in one place. Compare frequency of the disturbance for Observer A and Observer B explain

Frequency is the same. How do you know Frequency is the same. How do you know? Disturbances (waves) are the same distance apart (and will hit the each person with the same frequency)

Compare the speed of the disturbances as they reach A and B Compare the speed of the disturbances as they reach A and B. Which is faster?

Same speed

Compare the frequency of the disturbance produced by the bug bobbing up and down TO The frequency of the disturbance felt by A and B

SAME The frequency of the bug’s bobbing will be the same as the frequency of the disturbance felt by A and B

There is NO actual CHANGE in the frequency of the _____________.

Source of the disturbance

What direction is the bug traveling (right or left)? - For this lesson, The bug is producing disturbances at the ________ frequency as the chart below.

Travelling Right Same (both bugs are bobbing at the same frequency)

Where are the are the wavelengths longer (near observer A or observer B)

Longer near A (and shorter near B) (note how the distance between the lines of disturbance is greater near A)

Where is the frequency higher (near observer A or observer B)

Note: the disturbances hit B more frequently than A Higher near B (and lower near A ) Note: the disturbances hit B more frequently than A

Near Observer A each disturbance has a longer ______________________.

wavelength

Observer A experiences a frequency of arrival which is __________ than for B

lower

The name for the reason that B experiences greater frequency than A

Doppler Effect

What kind of waves can demonstrate The Doppler Effect

Any type of wave.

What are three types of waves that our class will use to observe the Doppler Effect?

Sound wave Light wave Water wave

Higher frequency means higher ______

pitch

lower frequency means lower ______

pitch

Which person will hear a higher pitch?

Higher pitch: The boy on the right (note that near the boy on the right, the waves are bunched together and are hitting the boy with a higher frequency; higher frequency = higher pitch)

Why does this person hear a higher pitch?

Sound waves are bunched together Sound waves are bunched together. The boy will hear a higher pitch because the waves are hitting him at a higher frequency.