Physics 5A, Spring Semester 2008
Cuesta College, San Luis Obispo, CA
Cf. Giambattista/Richardson/Richardson, Physics, 1/e, Conceptual Question 1.7 (extended)
Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the beginning of their learning cycle:
[0.3 participation points.] In general, what is the difference between an average and an instantaneous quantity?
(A) The amount of change that takes place.
(B) The amount of time for a change to take place.
(C) How fast the object is moving.
(D) The number of times that a change takes place in a given time interval.
(E) (I'm lost, and don't know how to answer this.)
Sections 4987, 4988
(A) : 7 students
(B) : 14 students
(C) : 1 student
(D) : 17 students
(E) : 3 students
Correct answer: (B)
For example, average velocity is defined as the displacement of an object divided by a finite time interval, whereas instantaneous velocity is defined as the vanishingly small ("infinitesimal") displacement of an object divided by a vanishingly small ("infinitesimal") time interval. Students seemed to confuse the semantics of the term "average" with the sampling of many results, as opposed to "instantaneous" being only one event.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment