The full grading rubric for quiz 2
Perfect score = 10. Extra credit = 2.
Part 1a (8 points) : vb = v1 ( 1 - v1 / (3 v_infty))
100 %: practically perfect
80 %: numerical coefficient error, but the form is good
75 %: answer is good, but not in the perturbation form
70 %: perturbation form with incorrect numerical coefficient and
overall sign error
70 %: got vb^2, correctly, but did not give vb
70 %: answer has numerical error and also is not in the perturbation
form
60 %: the perturbation correction term has incorrect powers
60 %: answer is very wrong due to a sign error in the steps, and is not
in the perturbation form
60 %: the answer is not finalized, while an approximately correct
answer is there
40 %: incorrect dimension, incorrect result
0 %: answer missing, or completely incorrect
Part 1b.1 (2 points) : h2/h1 = 1 - 4 sqrt{2} alpha / 3, where alpha = k
sqrt{h1/g}
100 %: practically perfect
90 %: got correct expression, but the perturbation form is cluttered
with unallowed, and complicating, higher order terms
85 %: got a nearly correct perturbation expression, but there are
numerical errors
80 %: got (nearly) correct expression, but did not turn it into the
final correct perturbation form, linear in k
60 %: v2 = vb was used, very incorrectly
60 %: got a perturbation expression, which is very incorrect
60 %: got a dimensionally incorrect result
60 %: answer is not approximately equal to 1
25 %: correct starting formula, but no or little development from it
0 %: answer missing, or completely incorrect
Part 1b.2 (2 points) : k = (3 / (4 sqrt(2))) * sqrt (g/h1) * (1 - h2/h1)
100 %: practically perfect
90 %: got correct expression, but cluttered with unallowed, and
complicating, higher order terms
80 %: got a dimensionally correct result, which is small (correctly),
but contains numerical errors
80 %: got a dimensionally correct result, which is small, but did not
express it as a function of h1, h2
70 %: the final answer is large, instead of being small
70 %: got an implicit formula, which is dimensionally correct and could
have given an almost correct answer if higher order terms were
ignored
70 %: dimensionally correct answer, but too small (e.g., second order
or higher)
70 %: got a dimensionally correct result, but the form was not
simplified using perturbation and intermediate steps have error
70 %: got a dimensionally correct result, but not small (not prop. to
(1 - h2/h1)) and has numerical errors
70 %: got a small result, correctly, which is however dimensionally
incorrect
60 %: got the final result, but dimensionally incorrect and not small
(not prop. to (1 - h2/h1))
50 %: got the final result, dimensionally incorrect, not small, and
t-dependent
50 %: got an implicit equation, dimensionally incorrect
25 %: correct starting formula, but no or little development from it
0 %: answer missing, or completely incorrect
Ph105-14