PhysicsDoppler effect

Key Terms Resonance- Interference Diffraction Photo-electric effect

Crest Trough Wavelength frequency Period Hz

nm speed of light speed of sound constructive interference destructive interference Photoelectric effect Transverse waves Longitudinal waves

Lesson Objective Students understand the key terms and

General concepts associated with electromagnetic waves and wave systems.

You will be successful if… If you can answer ½ of the questions on

the study guide given on Haiku.

Introduction Waves carry energy from place to place.

The amount of energy can be determined from the frequency and intensity of the wave. Higher frequencies have higher energy than lower ones.

Fun video or picture describing subject Train Doppler goes here

Light is an electromagnetic wave Sound is a wave due to longitudinally

vibrating molecules.

Heavy There is a maximum speed limit for light

and sound, Sound c= 343 m/s Light c= 300,000,000 m/s

HeavyAny movement due to a source or observer causes a compression or expansion of these waves. Which we call the Doppler effect.

Example- Bats use the Doppler effect to hunt.

Waves can interfere with eachother. This can cancel out a wave, or cause a super wave.

Lasers take advantage of this by reinforcing eachother.

Noise cancelling earphones take advantage of this by measuring then cancelling ambient noise.

With the basic idea’s out of the way, lets try some sample problems on Pear.

Lets practice

Pear deck

Sample problem- If two speakers with a wavelength of 1 meter are put ½ meter from eachother, at what point will there be silence in front of the speaker.

Quiz- If two waves interfere,and wave 1 had a crest twice as high as the trough of wave 2, what is the resulting height of wave one?

½ wave 1 They are the same

Equal to wave two

Equal to wave 2

before the interference.

Work for quiz (symbolic)

Did you meet the objective? Did you meet criteria for success- self

critique.

Our next lesson- thin film interference and polarization.

Link to Haiku

Classwork