About The Perpendicular Distance Calculator Biomechanics Tool

Definition

The perpendicular distance is the shortest distance between a point (axis of rotation) and a line (the extension of a line segment). For a force, the extended, imaginary line, is known as the line of action of the force.

Instructions

The concept of a perpendicular distance seems quite difficult for some students to grasp. Students need to have knowledge that a force has a magnitude and direction, and that in addition it has a point of application and a line of action. The Perpendicular Distance Calculator Biomechanics Tool displays a force with randomly generated (constrained) magnitude and direction, that acts on a segment of fixed length but randomly generated direction, at a point of application along the segment length.

The Perpendicular Distance Calculator Biomechanics Tool was developed to operate in two ways:

1. As an experiential learning tool where the students can click the Go button and generate the segment and force, and then choose to check boxes and display the "Show force line of action" and the "Show perpendicular distance". The angle that could be used to calculate the perpendicular distance is also displayed on the graph, and the calculated perpendicular distance is also shown.
2. As a testing tool where a subject who identifies the point where the perpendicular distance connects with the line of action of the force then clicks on the graphical display and gets feedback on whether they have correctly identified the point and therefore the perpendicular distance.

Geoff and James Strauss February 2011.