Calculating Speed of Light on a Spaceship: Earth Relative vs. Spaceship Relative

[tymartin]

Homework Statement

You're riding a fast spaceship going 7.52 x 107m/s and you turn on your flashlight. What's the speed of the light ray relative to the spaceship? What is its speed relative to the earth?

Homework Equations

The Attempt at a Solution

Deeply confused

 

[Doc Al]

Hint: Consider the postulates of Special Relativity. (You should be able to answer the questions immediately with no calculation.)