Accelerating a car from rest : friction, power and forces

• 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.

Subject headings

SAMHÄLLSVETENSKAP  -- Utbildningsvetenskap -- Didaktik (hsv//swe)

SOCIAL SCIENCES  -- Educational Sciences -- Didactics (hsv//eng)

SAMHÄLLSVETENSKAP  -- Utbildningsvetenskap -- Lärande (hsv//swe)

SOCIAL SCIENCES  -- Educational Sciences -- Learning (hsv//eng)

Keyword

acceleration

free-body diagram

friction

grading

graphs

power

pseudowork

free-body diagram

Publication and Content Type

art (subject category)

ref (subject category)