Accelerating a car from rest: friction, power and forces

This is the authors' abstract. We don't add key points for this paper.

The directions of frictional forces for bodies in motion are conceptually challenging. Students may be able to provide a correct solution using only calculus without drawing free-body diagrams. This can make their misconceptions go unnoticed and put them at risk to become further reinforced. Here, we discuss first-year bachelor students’ responses to multiple-choice questions and an open-ended question regarding friction when they come fresh out of high school. We further look into student solutions submitted to a national competition in physics for high-school students involving a problem concerning the acceleration of an electric rear-wheel drive car. Finding that most students had avoided drawing figures, we discuss to what extent teachers’ grading practices contribute to students’ development of problem-solving habits.