Many studies on physics learning report on the existence of misconceptions in students reasoning (e.g. when an object is at rest its acceleration is zero). Physics teachers are not always acquainted with this body of research. Moreover, many teachers think that only few and weak students in their classes have the misconceptions reported in the literature. In this paper we report on an activity with teachers focused on misconceptions in the physics classroom. The activity was carried out on-line through the website of the national center of physics teachers in Israel.

The activity dealt with the third law of Newton and had the following goals: to convince teachers about the inherent existence of misconceptions in this topic; to present physics education research findings about this topic; and to support teachers in designing new instructional strategies that promote conceptual understanding.

Website of the National Center of Physics teachers: http://stwww.weizmann.ac.il/ptc