F~1/r²
doubling the distance r, Decreases the force by ¼
The magnitude of the resultant force is given by the centripetal force, since the car is under a circular motion. So, we have:
The centripetal acceleration is given by:
Where v is the linear speed and r the radius of the circular motion. Replacing this and solving:
This shifts the star’s spectral lines toward the blue end of the spectrum. If the star is moving away from us, it’s waves are effectively stretched out when they reach earth, increasing their wavelength. This shifts the star’s spectral lines toward the red end of the spectrum.