Exam 1 Grading

[goodwine]

Points were allocated or taken away in exam one according to the following:

• Problem 1:
  • 5 points for an appropriate solution method
  • 5 points for computing the right solution
  • 5 points for finding the time
  • 7 points for determining the right equation in part (b)
  • 3 points for the right initial condition for part (b)
• Problem 2:
  • 10 points for determining the homogeneous solution (7 for the method, 3 for the right answer)
  • 10 points for determining the particular solution (7 for the method, 3 for the right answer)
  • 5 points for putting them together in a linear combination for the general solution
• Problem 3:
  • 5 points for the correct homogeneous solution
  • 10 points for the correct particular solution
    • 8 points for the right method (4 points for multiplying by t, 4 points for using a constant term)
    • 2 points for the correct algebra and answer
    • 5 points for VoP but that didn't get to a final answer
  • Graph: 5 points for a decaying oscillation, 5 points for recognizing that the steady state value was not zero. A good guess on the graph based on only partial work in part (a) was given 2 points.
• Problem 4:
  • 10 points for a correct method (-5 points for the wrong C)
  • 5 points for the correct answer (-3 for a wrong sign)
  • 10 points for the graph
    • 5 points for the correct trends
    • 5 points for all the curves going through x=1 at t=0
    • -3 for wrong shape
    • -3 for no labels
    • -2 for not on the same graph
    • -4 for missing one of the lines on the plot.

There is "double jeopardy." If you make a mistake that propagates through the problem, points were deducted for the subsequent parts, but generally only 1 or 2 points.