1) The digital sign outside a local bank reports that the temperature is
   44 degrees C. What is the temperature in degrees Farenheit?

    T = 44 * 9/5 + 32 = 111.2

2) Absolute zero on the Celsius scale is -273.15 degrees C. What is the
   absolute zero on the Farenheit temperature scale?

    T = -273.15 *9/5 - (-32) = 459.67

3) Which of the following statements concerning time dilatation is true?
  a) It is predicted by general relativity, but has never been observed.
  b) It has been observed only in experiments involving radioactive decays.
* c) It has been observed in experiments involving both atomic clocks and 
     radioactive decays.
  d) It has been disproved in experiments with atomic clocks.

4) In year 2097 an astronaut wears an antique but accurate "quart" wristwatch
   on a journey at a speed of 2 10^8 m/s. According to mission control in
   Houston, the trip lasts 12 hours. How long was the trip as measured on the
   watch?

    T = T' * sqrt[1-(2 10^8/ 3 10^8)^2] = 12 hr * sqrt[1-4/9] = 8.94 hr


5) Complete the following statement: To measure the proper length of an object
   moving relative to the surface of the Earth, one must note the coordinates
   of points on the front and back ends

  a) at the same time with respect to a clock at rest on the Earth.
  b) at different times  with respect to a clock on the moving object.
* c) at the same time with respect to a clock on the moving object.
  d) at different times with respect to a clock at rest on Earth.
  e) at the same time with respect to a clock moving at the same speed on the
     surface of the Earth.

6) A spaceship leaves our solar system at a constant speed of 0.900 c
   and travels to a point in the Andromeda galaxy. According to astronomers in
   an inertial reference frame on Earth, the distance to the galaxy is
   2.081 10^22 m. What distance does the crew on the ship measure on its
   journey? 

    L' = L * sqrt[1-beta^2] = 2.081 10^22 m * sqrt[1-.081] = 9.07 10^21 m