In a Summer camp organized by the city Police you are standing on a bridge over
ID: 2198440 • Letter: I
Question
In a Summer camp organized by the city Police you are standing on a bridge over a highway measuring the speed of the cars with a handheld Doppler radar. Complete the following statements. Options: Increases, Decreases, Stays the same If a car is receding away from you, the speed of the reflected radar wave ... . If a car is receding away from you, the frequency of the reflected radar wave ... with respect to the original frequency. If a car is approaching you, the wavelength of the reflected radar wave ... with respect to the original wavelength.Explanation / Answer
If a car is receding away from you, the speed of the reflected radar wave stays the same.
(The speed of waves does not change. The formula is v = f. Frequency and wavelength will change. As one increases, the other will decrease at the same rate to make the speed remain unchanged)
If a car is receding away from you, the frequency of the reflected radar wave decreases.
(The waves will not get back to the gun with the same frequency since the car keeps going away, it takes longer each time since the distance to travel keeps growing)
If a car is approaching you, the wavelength of the reflected radar wave decreases.
(The waves will be 'crunched' together since the car is getting closer, its as if the car is pushing the waves together reducing the distance between them, which is the wavelength.)