Laboratory for 2/9/98

Below are a few sample questions from a previous exam. The test will not be open book (as suggested earlier), but you will be allowed to bring an equation sheet. The sheet may not have any worked or outlined problems on them. May the Force of Relativity be with you.

• A spacehip leaves Earth at speed .9682c for Alpha-Centauri, which is 4.2 lyr away. How long does the trip take according to those on earth. How long for those on the ship? Briefly explain how the ship passengers and earth-bound observers agree with each others calculations.
• A car with proper length 20 ft travels at such a speed that a ground observer measures its length to be 16 ft. According to the ground observer, how long does it take the car's clock to register 1 second? According to the car passengers, how long does it take the ground observer's watch to register 1 second?
• Beldar tells Premat that he is traveling on a business trip in his ship at .98c. He promises to send a photon note every one of his days.
  • How often would she receive the notes during his outward journey?
  • In fact, Beldar is circling the earth at .98c while partying with space bunnies. How often does Premat actually receive the notes?
  • A proton is accelerated until its total energy is twice its rest energy.
    • What is the protons kinetic energy?
    • How fast is the proton moving?
    • If it collides with another proton at rest, is there enough energy to produce another (3 total) protons? Explain.

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