Little time for warning of Mir crash disaster


  1. How fast is the speed of sound?
    Why do we have a specific name for this speed?
    Why is it useful to categorise this speed as a certain number?
  2. If Mir weighs 135-tonnes, how many 700kg chunks could it break into?
  3. How fast would large pieces of debris be falling if they were travelling as fast as a passenger jet?
    Would smaller pieces fall faster or more slowly?
  4. Why will 90% on Mir burn up on re-entry?
    How much will the remains of Mir weigh after re-entry?
    Why will pieces of debris be "scorching hot"?
  5. If Mir has a present altitude of 60km today and is getting closer by 1.4 km per day, how long from today will it take to reach Earth?
    Are these the same data as stated in the article?

(Written by Karen Scriven, BTeach student, University of Tasmania, 2001)


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