# Grading Rubric - Confusing force and position vectors....

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Grading Rubric for Homework and Exams Ex: (-1)(-1) = -1 Ex: - (-7(-2) +3) = +17 (Losing a negative sign while distributing.) Ex: - (-7(-2) +3) = -14 (Simple multiplication error.) +/- error in just the math. Ex: -10sin30 = F x F x = 5 (Transcription error.) Missing answer arrow. Missing units on final answers. Missing or incorrectly used vector arrows or hats. Forgetting to cite substitutions. Forgetting to put = 0 on a FBD for equilibrium. - 1 Four significant figures. (Only once per problem.) sin/cos error Missing diagram Messing up the projection line Ex: Failure to recognize a negative vector direction. Plot reading error Ex: Mixing up the x and y-axes. Ex: Angles switched Incorrect FBD Ex: Equal & opposite connecting (internal) vectors drawn in the same direction. Ex: In x direction: Ex: Σ F x = 0 Failure to cite a basis Ex: R x = Σ r x - 2 Forgetting negative root α = cos 1 ± 1 cos 2 β cos 2 γ = cos 1 ± 1 cos 2 60 cos 2 = 72 ,108 ( ) By inspection . . . Ex:
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Unformatted text preview: Confusing force and position vectors. Using = tan 1 F y F x instead of , , and in 3D. Ex: Forgetting to normalize the unit vector. - 3 Wrong equation Ex: Forgetting to square the magnitude components under the root sign. - 5 Returning a vector answer for a dot product calculation. For incomplete work give the points commensurate with the percentage of the overall work done. Example: If a 35 point problem has 7 steps and they complete 2 of the steps, give them 10 points. Don't take off more than what the problem is worth! Make sure they end up with at least 5 points for trying on an exam and 2 points for trying on a homework problem. (If they did try . . .) Homework Only For work too messy, small, etc, grade, but return to the student to resubmit a better copy before recording. Zero for the whole assignment if the correct answer follows from incorrect math....
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## This note was uploaded on 02/06/2012 for the course CEEN 103 taught by Professor Stephanieallredmagleby during the Winter '12 term at BYU.

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