The status of Galileo’s law of free-fall and its implications for physics education

Abstract

We have examined the understanding of students and physics teachers regarding Galileo’s law of free fall. Refining this law for an observer on the ground, which is usually neglected in textbooks, results in the acceleration of free fall being mass dependent. We found that physics students and high school teachers are unaware of the conditions for which Galileo’s law is valid, and the law is often identified with the equivalence principle.