Kepler’s Second Law Using Integration by Weighing

Abstract

Kepler’s second law, also known as the law of equal areas, can be difficult for introductory students to explore using actual data given the complexity of the formula for finding the area of a sector of an ellipse. It is also possible to demonstrate Kepler’s second law with simplified math using video analysis of objects in a gravitation funnel if students have access to the necessary materials. In this activity, students discover Kepler’s second law using minimal equipment and mathematics using the technique of integration by weighing, where students cut out sections of an ellipse and use the mass of the sections to compare their areas.