Appendix C: Guidelines for Interactive Scoring

Part (d)(i) earned 1 point for the numerical comparison, but the explanation was not correct for an actual speed that is greater than the predicted one. Part (d)(ii) earned no

The second data point was incorrectly plotted and no credit was earned for the smooth curve illustrating the increasing velocity of the glider..

One point was lost in part (c) for an incorrect expression for the kinetic energy; the remaining 2 points were earned for solving the expression for the speed and substituting

In part (c) students were not given the bar’s center of mass, and they were asked to describe an experimental procedure, including the necessary equipment, that could be used

Part (a) earned 2 points in the alternate solution for use of the correct kinematics equation and a correct substitution of the distance d into that equation; no valid work is done

For example, if an incorrect answer to part (a) is correctly substituted into an otherwise correct solution to part (b), full credit will usually be awarded.. One exception to this

For correctly drawing and labeling T, the tension in the cord, or its components 1 point For correctly drawing and labeling Mg, the weight of the rod 1 point For correctly

If the student had brought down the first equation from part (d)(i) to (d)(iii), 1 point would have been received since that equation is a correct general expression, but the specific