Special relativity noob problem 2, Dopler shift.

[-Vitaly-]

Homework Statement

By 2025 a spaceship shuttle service operates between the Earth and Mars. Each
spaceship is equipped with identical mono chromatic head and tail lights, and their cruising speed v relative to earth, is such that the headlight of a homeward-bound spaceship appears green ( lambda = 500 nm) and the tail-light of a departing spaceship appears red(lambda = 600 nm).(i) What is v/c ?(ii) What is the wavelength of the headlight of an earth-b ound spaceship is observed froman outward b ound one?

Homework Equations

http://hyperphysics.phy-astr.gsu.edu/hbase/relativ/reldop2.html"

The Attempt at a Solution

I have no idea where to start.

 

[tiny-tim]

Each
spaceship is equipped with identical mono chromatic head and tail lights …

Hi -Vitaly-!

The two lights are the same colour, but they look different because of the Doppler shift.

Just plug in the equations, and see what happens!