An enemy spaceship, which is moving at high speed away from the planet Arrakis, fires a rocket toward the planet with a speed of 0.910 cc relative to the spaceship. (See (Figure 1).) A commander on Arrakis reports that the rocket is approaching with a speed of 0.500 cc. What is the speed of the spaceship relative to Arrakis? Express your answer as a multiple of speed of light cc.

A proton has momentum with magnitude p0 when its speed is 0.400c. In terms of p0 , what is the magnitude of the proton’s momentum when its speed is doubled to 0.800c?

A particle has γ=18,399.  a) Calculate c-v in m/s.  (I would have asked for 1 - v/c, making the answer dimensionless, but the system doesn't seem to take numbers that small.  Gamma is chosen to make the particle extremely close to the speed of light.) If your calculator gives problems, you might want to solve the appropriate equation for c-v or c(1 - v/c) and use an approximation. b) In a race to the moon, by 3/4ths the distance, light is one or ten meters ahead of the particle.  We routinely approximate mass as zero, gamma as infinite, and speed as the speed of light.  ("Massless particles" -- gamma and m have to be eliminated from the expressions.  Light is a true massless particle.) If a massless particle has momentum 1,739 MeV/c, calculate its energy in MeV. Thank you so much!!

Consider the inelastic collision. Two lumps of matter are moving directly toward each other. Each lump has a mass of 0.500 kg and is moving at a speed of 0.930c. The two lumps collide and stick together. Answer the questions, keeping in mind that relativistic effects cannot be neglected in this case. What is the final speed uf of the combined lump, expressed as a fraction of c? 1.27 Uf = C Incorrect What is the final mass me of the combined lump immediately after the collision, assuming that there has not yet been significant energy loss due to radiation or fragmentation? 2.70 mf = kg