Tackling contradictions in teachers’ understanding of gravity and air resistance

Abstract

Concerns over teachers’ knowledge of science, particularly their understanding of forces, are reviewed. The article reports a study which explored the understanding of gravity and air resistance among a group of primary teachers on an in‐service course. Two main misconceptions were identified. The first, that heavy objects fall more quickly than light ones, seemed to arise from seeing the effect of air resistance on the descent of light objects. The second, that gravity pulls all objects equally, seemed to arise from the observation that all objects which are heavy for their size fall at approximately the same rate. The idea that the forces from air resistance and gravity are balanced when terminal velocity is reached was also resisted by the teachers who felt that an object must be stationary when there is no resultant force. A sequence of teaching which tackled these misconceptions and the teachers’ difficulties with balanced forces was evaluated. The discussion considers ways in which such work may best be done with primary teachers to increase the knowledge base of the profession.