Student performance on the “unconnected-spools” problem and the “connected-spools” problem (see Figs. 5 and 6). In both cases students were
asked to compare the center-of-mass accelerations of the two spools and to predict which spool will strike the ground first. Results were obtained before tutorial
instruction on the topic and after varying degrees of exposure to the topic of rigid body dynamics in lecture, textbook and lab. Percentages are with respect
to the total number of students who responded. Responses were categorized without regard to the explanation given