Exam 1 Grading
Posted: Fri Sep 25, 2009 9:33 am
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.