Things to do and questions to answer

• For the case of no damping measure the velocity of propagation of elastic waves up the skyscraper. Is the velocity a function of frequency (i.e. is this a dispersive medium)? Is the value of velocity what you might expect ?
  There are two characteristic frequencies in this system, the frequency of the earth driving force and the resonant frequency of the elastic oscillation. If these are the same one expects a resonant response. You need to be aware of this when investigating the frequency dependence of anything.
  
• Why is simply stiffening the building without damping unlikely to be satisfactory protection against earthquake damage? (Assume there is always a component of driving force at the resonant frequency of the building).Show how damping can be used to withstand earthquakes.
  
• Study the case of heavy damping ( ). Can you explain the various phenomena observed qualitatively?
  
• Note that the derivatives routine multi.c has no comments. It is your task to explain how multi works by adding comments - at least one per line.
  You need to understand how cplos runge and multi work together because you will have to organize the moonshot program yourself.

Use of plstyl() in C programs
Refer to page 73 of the plplot manual. When using plstyl in C programs it is necessary to define arrays mark and space whose elements hold the lengths (in microns) of mark-space pairs.
For example :

		int mark[4],space[4]; /* Allow up to 5 mark-space components */
		mark[0]=1000; space[0]=1000; /* Units are microns */

		plstyl(1,mark,space); /* Simple mark-space each 1mm long */

Note that it is good to add copious comments to source code. Comments can be inserted anywhere in the program by enclosing them in /* .... */ .