Force Table

Related Physics Education Research

Arnold Arons A Guide to Introductory Physics Teaching.

Overview of Worksheet

Students use force tables to see that forces add as vectors (or, more concretely, that they can balance two weights by a single third weight where the magnitude and location of the third weight is calculated by adding the components of the original two weights). Students use their understanding of trigonometry to solve this problem.

Approximate Time

One hour.

Required Student Background

Students need to be familiar with trigonometry. If trig ideas have not yet been used in the course, a review is probably necessary. Students do not need to know any more about forces than they have surely already learned from everyday experiences of balancing.

Connections to the Tutorials

The tutorials emphasize graphical vector addition, in this worksheet and the vector addition worksheet, we focus on numerical vector addition.

Required Equipment

A force table and weights.

Evaluation of Worksheet

One evaluation came in listening to the students who were clearly initially challenged by the lab, but all students were at least beginning to make sense of the ideas by the end of the hour. The second evaluation came from the dynamics test for which we asked about the forces acting on a ball suspended by a string and blown by a constant wind. The class who used this worksheet got 38% correct, the class without got 28% correct. (This was a multiple choice question with some very tempting wrong choices!) Further analysis showed that this difference was not statistically significant.