Observer a Measures the Velocity of a Rocket as

Multiple Choice

Observer A measures the velocity of a rocket as and a comet as . Here are parallel and in the direction of the observer's positive x axis. The speed of the comet as measured by an observer on the rocket is:

A) (u - v) /(1 - uv/c²)
B) (u - v) /(1 - v²/c²)
C) (u - v) /(1 - v²/c²) ^1/2
D) (u - v) /(1 + uv/c²)
E) (u + v) /(1 - uv/c²)