1. In the spectrum of the bright star Rigel, has a wavelength of 656.331 nm. Is the star coming toward us or moving away from us? How fast? 2. Imagine driving down a street toward a traffic light....

1. In the spectrum of the bright star Rigel,

has a wavelength of 656.331 nm. Is the star coming toward us or moving away from us? How fast?

2. Imagine driving down a street toward a traffic light. How fast would you have to go so that the red light (700 nm) would appear green (500 nm)? What fraction is this of the speed of light, c (c = 300,000 km/s)?