20180911

Physics quiz question: displacement and/or distance traveled?

Physics 205A Quiz 2, fall semester 2018
Cuesta College, San Luis Obispo, CA

The vx(t) graph of a Physics 205A student walking along a straight line is shown at right. The student started at x = 0 at t = 0. The shaded area is the student's __________ for the time interval 4 s ≤ t ≤ 8 s.
(A) displacement.
(B) distance traveled.
(C) (Both of the above choices.)
(D) (Neither of the above choices.)

Correct answer (highlight to unhide): (C)

The displacement of the student is the area bounded by the student's vx(t) graph and the time axis. Since the student is always traveling in the forward direction (as all the velocity values are positive during this time interval), then the distance traveled is the same as its displacement.

Sections 70854, 70855
Exam code: quiz02HwRd
(A) : 16 students
(B) : 10 students
(C) : 20 students
(D) : 6 students

Success level: 38%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.80

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