(a) Reference frame S' moves with speed v relative to a resting frame S. Derive the speed u of a particle measured in S in terms of the u measured in S and v, using the Lorentz transformation. (b) An enemy spaceship is moving toward your Starfighter with a speed, as measured in your frame, of 0.4c. The enemy ship fires a missile toward you at a speed of 0.7c relative to the enemy ship. What is the speed of the missile relative to you? Express your answer in terms of the speed of light.

(a) Reference frame S' moves with speed v relative to a resting frame S. Derive the speed u of a particle measured in S in terms of the u measured in S and v, using the Lorentz transformation. (b) An enemy spaceship is moving toward your Starfighter with a speed, as measured in your frame, of 0.4c. The enemy ship fires a missile toward you at a speed of 0.7c relative to the enemy ship. What is the speed of the missile relative to you? Express your answer in terms of the speed of light.