Student Misconceptions About Tangential Acceleration in Curved Motion

Understanding acceleration in curved motion is critical for mastering introductory physics concepts, yet persistent misconceptions remain. In this study, we investigate University Physics I students' conceptual difficulties with tangential acceleration in non-uniform circular motion. When presented with a problem involving a car moving along a circular path with decreasing speed, a majority of students successfully calculated the magnitude of the total acceleration, correctly combining radial and tangential components. However, when asked to represent the direction of the acceleration vector, many students incorrectly identified the acceleration as pointing solely toward the center of the circle, neglecting the tangential component entirely. Analysis of written responses suggests that students often associate "acceleration in a curve" exclusively with radial acceleration, failing to recognize the role of changing speed along the path. Possible cognitive sources of this misunderstanding and suggestions on instructional strategies to better support student reasoning about multi-component acceleration vectors in two-dimensional motion are discussed.