Q1. A spaceship is coming directly toward you while you are in the international space station. You are told that the spaceship is shining sodium light. You have an apparatus that and resolve two closely spaced wavelengths if the difference is 0.55 nm. If you find that you can just resolve doublet, how quick is the spaceship travelling with respect to you.

Q2. A person rides on the Ferris wheel that rotates with constant angular speed. If the Sun is directly overhead, does the person's shadow on the ground undergo periodic motion?