Many pupils think that an object that is moving along a curved path will continue to follow a curved path when its motion becomes unconstrained.
Resources to Address This
Whirling a rubber bung and letting go (11 - 16)
Source - Practical physics/ Force and motion/ Circular motion
This resource is used in the classroom to show the tangential motion of an object when it is released from circular motion.
Also - Introduction to circular motion - another activity in the same group.View Resource
Going around in circles (11-14)
Source - SPT/ Es02PN02
Demonstrate that When the string is cut the centripetal force is removed and the bung leaves its circular orbit, continuing along a tangential path.View Resource
The following studies have documented this misconception:
- Bliss, J., Morrison, I. and Ogborn, J. () A longitudinal study of dynamics concepts. International Journal of Science Education, 10 (1),
This study examined the concepts of dynamics held by students across a range of year groups using written tests and follow-up interviews. The sample consisted of 87 students between the age of 12 and 16 from three different schools in the UK.
- McCloskey, M., Caramazza, A. and Green, B. () Curvilinear Motion in the Absence of External Forces: Naïve Beliefs About the Motion of Objects. Science, 210 (4474),
University students were asked to draw the path a moving object would follow in several different situations. Over half of the students, including many who had taken physics courses, evidenced striking misconceptions about the motion of objects. In particular, many students believed that even in the absence of external forces, objects would move in curved paths. The sample comprised 47 students, 15 of which had no formal physics education, 22 of which had high school physics, and 10 of which had college-level physics.