Newton's Second Law: F=ma

Related Physics Education Research

Arnold Arons A Guide to Introductory Physics Teaching

D. Dykstra (1996). Teaching Introductory Physics to College Students. Constructivism: Theory, Perspectives, and Practice. C. T. Fosnot. New York, Teachers College Press.

J. Minstrell (1982). Explaining the "at rest" condition of an object The Physics Teacher 20: 10-14.

Overview of Worksheet

This worksheet is a write-up of Professor Dewey Dykstra's lesson outlined in the reference above. The only change I made was to have students do the work in groups instead of in a class as a whole. Prof. Dykstra's students are mostly non-engineering with less background in physics. Most of our students have had physics in high school; I hoped that in small groups confusions about the already familiar F=ma might be more likely to surface than in a large group discussion. In observing students in class, there were indeed many valuable discussions going on.

Approximate Time

An hour.

Required Student Background

Students need to be familiar with velocity and acceleration. Their everyday experiences with friction and force will also come into play.

Connections to the Tutorials

No direct connections.

Required Equipment

Low friction carts, tracks, hanging weights, force probe, and MBL equipment.

Evaluation of Worksheet

We used the Force Concept Inventory that measures student understanding of basic kinematic and dynamic concepts and which was introduced by I. A. Halloun and D. Hestenes in The initial knowledge state of college physics students in American Journal of Physics 53, 1043 - 1055 (1985).

To take into account previous knowledge, the FCI is typically given twice: once before instruction and once after. Scores on the FCI are reported as percent gain: post test - pre test score / perfect score - pre-test score. This measure the fraction of what they could have learn, that they learn.

We used our own class as a control, in that the activities did not work well the Fall 1998 semester, and were reworked for the Fall 1999 semester.

For Fall 1998, our students percent gain was 25% +/- 45% (17 students), for Fall 1999 45% +/- 28% (43 students) the second year. The second year score is in line with national averages for interactive-engagement classes, see R. R. Hake Interactive-engagement versus traditional methods: A six-thousand-student survey of mechanics test data for introductory physics courses in American Journal of Physics 66, 64-74 (1998). We feel these improvements in scores were made possible by improved worksheets.