PHY131H1F Fall 2014 - Some Images of Marked Tests

Here is my marking philosophy:

If you get the exactly correct answer, including significant figures and units, and write that answer in the box provided, and show your work in the space above the box, you should get 100% for that part.  If your final answer is wrong, then some partial credit may be awarded based on the work you showed.  To see the full solutions for Test 1, with the scheme for awarding partial credit, please click here.

Below are some images of tests, showing some examples of how partial credit was awarded.  Please look through these examples and look carefully at the posted solutions before approaching Dr. Harlow with questions about partial credit.  Thanks!

Part A Examples

Below, question 1 is incorrect for the following reason: The student made the assumption that after the fuel is exhausted, the rocket suddenly comes to a stop.  This is incorrect: the final velocity of the first segment becomes the initial velocity for the next part of the motion, which is freefall.  5 points of partial credit were awarded for question 1 for correctly calculating the final height of the first segment of motion.    Question 2 is also incorrect, for the same reason as question 1: there is a bad assumption about the rocket suddenly stopping when the fuel is exhausted.  5 points of partial credit were awarded for correctly calculating a freefall time based on the bad assuption of v_initial=0.  Mark for part A: 10/20.

Below, everthing is correct except the student did not round the final answers to the correct number of significant figures.  0.5 marks were deducted per answer for incorrect use of significant figures.  Mark in part A: 19/20.

Below, question 1 is perfect except the number of significant figures is incorrect: 9.5/10 for question 1.  Question 2 is incorrect due to a bad assumption about the rocket suddenly stopping when the fuel is exhausted.  5 points of partial credit were awarded for correctly calculating a freefall time based on the bad assuption of v_initial=0.  Mark for part A: 14.5/20.

Part B Examples
Below, question 1 is incorrect because the error of the mean was not determined.  Instead the student reported standard deviation as being the error in the mean, which is not correct.  8 points of partial credit were awarded for question 1 based on correct work shown for calculating the mean and standard deviation.  Question 2 is perfectly correct for 4 points.  Mark in part B: 12/20.



Below, question 1 was answered correctly.  Question 2 was incorrect for the following reason: instead of finding how many measurements lie within 1 standard deviation of the mean, as asked, the student counted how many measurements lie within 1 error of the mean of the mean.  Zero partial credit is awarded for question 2.  Mark in part B: 16/20



Below, question 1 was done correctly, but question 2 was incorrect.  Rather than counting measurements within 1 standard deviation of the mean, the student made a prediction based on the assumption of a perfect gaussian distribution, which is not correct.  2 points of partial credit were given for this reasoning in question 2.  Mark in part B: 18/20.



Below, everthing is correct except the student did not follow the proper rules for rounding errors to 1 or 2 significant figures, then rounding the value to the same digit as the error.  0.5 marks were deducted per answer for incorrect use of significant figures.  Mark in part B: 19.5/20.