Mathematics 210 - Spring term 2003 - seventh assignment

This assignment requires you to submit several spreadsheets concerned with solving differential equations. This lab and the re-done mid-terms are due Wednesday, March 19, by class time. I repeat the instructions from the first lab:
  • Go to the MathSheet home page and then to the applet page. Open a running copy of the spreadsheet and return to this page.
  • Log in immediately: File/Log in. Your login id is your Mathematics Department login name, and your password is your student number. This allows you to save and load spreadsheet files. You should save your work frequently. The graph signature mechanism should now be working - please use this feature.
  • Question 1. Use the spread sheet to solve the differential equation dy/dt = -y + cos(2t) and initial condition y(0) = 1 with step size dx = 0.1 for the range t=0 to 20. Do this by each of the three methods explained in class: Euler's, Improved Euler's, Runge-Kutta of order 4. Do all of these on one sheet. Graph the solutions you get.

    Save this sheet as m210.7.1.ms.

  • Question 2. Use the spread sheet to solve the differential equation dy/dt = -y + t and initial condition y(0) = 1. Use Improved Euler over the range 0 to 6. Find roughly the largest step size you can that will give you an answer at the end correct to 4 decimals. Graph your solution.

    Save this sheet as m210.7.2.ms.

  • Question 3. An object at the surface of the Earth accelerates at 9.8 m/s2. The radius of the Earth is 6370 kilometers. If you drop an object from rest at a distance of 10,000 kilometers from the centre of the Earth, how long does it take for it to hit the Earth? Answer correct to 1%. Ignore air friction. Explain your accuracy.

    Save this sheet as m210.7.3.ms.

That's it!

If you find these questions confusing, please write me.