Student understanding of wave behavior at a boundary: The limiting case of reflection at fixed and free ends

American Journal of Physics

Volumn 79, Issue 5, 2011, Pages 508-516

  Kryjevskaia, Mila ^a   Stetzer, MacKenzie R ^b   Heron, Paula R L ^b  

^a NORTH DAKOTA STATE UNIVERSITY   (United States)

^b UNIVERSITY OF WASHINGTON   (United States)

Author keywords

[No Author keywords available]

Indexed keywords

EID: 79954533284     PISSN: 00029505     EISSN: None     Source Type: Journal    
DOI: 10.1119/1.3560430     Document Type: Article

References (13)

1. Tongchai A. Sharma M.D. Johnston I.D. Arayathanitkul K. Soankwan C. Maurines L. Spontaneous reasoning on the propagation of visible mechanical signals. Int. J. Sci. Educ. 1992, 14(3):279-293. ISEDEB, 0950-0693, 10.1080/09500690802389605, ISEDEB, 0950-0693, 10.1080/0950069920140305, For example, see and.
2. Wittmann M.C. Steinberg R.N. Redish E.F. Wittmann M. Making sense of how students come to an understanding of physics: An example from mechanical waves. Phys. Teach. 1999, 37(1):15-21. PHTEAH, 0031-921X, 10.1119/1.880142, and Ph.D. thesis, Department of Physics, University of Maryland.
3. Kryjevskaia M. Stetzer M.R. Heron P.R. L. Kryjevskaia M. Stetzer M.R. Heron P.R. L. Student understanding of wave behavior at a boundary: Transmission and refraction of periodic waves. Other results are reported in and (to be published), and (to be published).
4. McDermott L. Shaffer P. Tutorials in Introductory Physics 2002, Physics Education Group at the University of Washington, and and the (Prentice-Hall, Upper Saddle River, NJ, ).
5. Giancoli D. Knight R.D. Tipler P.A. Mosca G. Physics for Scientists and Engineers 2008, Several different textbooks were in use in this course during this investigation, including 3rd ed. (Prentice-Hall, Upper Saddle River, NJ, ), (Pearson Education, Inc., publishing as Pearson Addison-Wesley, San Francisco, CA, ); and and 6th ed. (Freeman, New York, ). In this case, as in others in our experience, we did not observe any systematic variation in student responses to pretests or post-tests that could be attributed to the textbook.
6. The shapes of the pulses were exaggerated for clarity. Although pulses on springs do not have straight edges and kinks, this simplification served multiple goals: students could more clearly follow the procedure of point by point addition of the overlapping pulses, and TAs and researchers could more easily analyze student drawings and unambiguously identify errors.
7. The model for linear superposition taught in the tutorial is consistent with the typical treatment in introductory textbooks.
8. This result does not hold generally for wave motion. However, the goal of the instruction is to develop a model for pulse propagation for situations in which this result is valid to a good approximation. Students observe that there is no significant difference in the propagation speed as transverse pulses of various widths and amplitudes travel along a spring during a short period of time. The difference in the speed becomes apparent only after the spring is changed (for example, stretched more).
9. French A.P. Vibrations and Waves 1971, 253-259. See, for example, the discussion in (Norton, New York, ), pp.
10. Out of the 12 locations at which the transverse displacement due to pulse 2 can easily be calculated, shapes were considered nearly correct if, at most, only one or two of those points were incorrectly determined.
11. The circumstances under which pretests and post-tests are administered differ. For example, students gain participation credit for attempting the pretest, whether or not their answers are correct. Also, on web-based pretests, students can, in principle, consult websites, textbooks, or each other. However, our experience is that student performance is not significantly affected. Although no group of students took more than one post-test, we have found that there is typically no variation from class to class. Therefore, provided the post-test is at least as difficult as the pretest, and that the post-test cannot be answered by memorization, it is possible to determine whether student understanding has improved by comparing percentages of correct answers.
12. The modified assignment was designed such that the amount of time students were expected to spend on the homework is roughly the same as what they would have spent on the original assignment that focused on simple pulses only.
13. Kozhevnikov M. Thornton R. Real-time data display, spatial visualization ability and learning force and motion concepts. J. Sci. Educ. Technol. 2006, 15(1):111-132. JSEEEP, 1059-0145, 10.1007/s10956-006-0361-0, For an example of a related study, see and.