Doppler
Doppler Effectfo = fs ( V + vd)/ (V-vs)
fo = frequency observed fs = frequency of source
V= speed of sound(343 m/s)
vd = speed of observer
vs = speed of source
+ towards each other,
- away from each other
1. A train is moving toward you with a velocity of 20 m/s and blows a whistle with a frequency of 120 Hz. What frequency do you hear? 127Hz
2. Two cars approach each other, each with a velocity of 50m/s one is honking a horn with a frequency of 200 Hz. What frequency does the other driver hear?
268Hz
3.What frequency does the the other driver hear after they pass and are moving away from each other?
149Hz
4. A train is moving toward you and blows a whistle with a frequency of 150 Hz you hear a frequency of 154 Hz. How fast is the train moving?
9.0 m/s