Chapter 26, Problem 7P

If you detected radio signals with an average wavelength of 20.000 cm and suspected that they came from a civilization on a distant Earth-like exoplanet, roughly how much of a change in wavelength should you expect to detect as a result of the orbital motion of the distant exoplanet? (Hint: Use the Doppler shift formula, Eq. 7-3.) (Note: Earth’s orbital velocity is 30 km/s.)