1. The problem statement, all variables and given/known data The wavelength of a particular ultraviolet radiation from hydrogen atoms is 1.216 e-7 m. Calculate the wavelength when the corresponding radiation from hydrogen in a distant galaxy is observed here on earth. The galaxy is receding at a speed of 0.11 c. 2. Relevant equations 3. The attempt at a solution I'm not sure what to do with the "receding at a speed of .11c" to solve this problem.. suggestions?