
A star orbits another much heavier one in an elliptical orbit as shown below.
The light received from the star at Earth will be alternately shifted to the red and blue, which of the following statements is true
A police speed trap calculates the speed of a car by using the Doppler shift produced when an electromagnetic wave is reflected off a moving car. To beat the trap the car could send a different frequency wave back to the policeman, the wave should be
You stand on the sidewalk next to the street. A fire truck is moving towards you. The frequency of the siren on the fire truck is 600 Hz.
What should you hear?
You stand on the sidewalk next to the street. A fire truck is away from you. The frequency of the siren on the fire truck is 600 Hz.
What should you hear?