Download Doppler Effect- change in frequency of a moving object

Doppler Effect- change in frequency of a
moving object
How can you tell if an ambulance is moving
towards you or away from you?
 By a change in its pitch.
If a sound is moving toward you waves are
getting squished.
 Squished Waves = Short Wavelength =
High Frequency = High Pitch
If a sound is moving away from you waves
are getting stretched.
 Stretched Waves = Long Wavelength =
Low Frequency = Low Pitch
What would happen to the light of a star or
galaxy if it is moving towards us or away
from us?
 If a light source is moving away, the light
waves will get stretched. This means the
light waves are getting longer and the
frequency is getting lower.
 Light moving away = Red Shift
 If the light source is moving towards an
observer, the light waves will get
squished. This means the light waves are
getting shorter and the frequency is
getting higher.
 Light moving towards = Blue Shift