Cuesta College, San Luis Obispo, CA
Cf. Giambattista/Richardson/Richardson, Physics, 1/e, Problem 2.40
[3.0 points.] Consider the v_x(t) graph of an object moving along a straight line, as shown at right. How far did the object move between t = 3.0 s to t = 6.0 s? (A) 1.5 m.
(B) 7.5 m.
(C) 13.5 m.
(D) 21.0 m.
Correct answer: (C)
Displacement is the area bounded by the v_x(t) graph in the time interval, which is the area of a triangle (7.5 m) and the area of a rectangle (6.0 m) added together, giving a displacement of 13.5 m. Response (A) is the difference of the triangle and rectangle areas; response (B) is the area of only the triangle; while response (D) is the twice the triangle area added to the rectangle area.
Student responses
Sections 70854, 70855
(A) : 0 students
(B) : 15 students
(C) : 29 student
(D) : 3 students
"Difficulty level": 61%
Discrimination index (Aubrecht & Aubrecht, 1983): 0.08
No comments:
Post a Comment