Isn't the spike on the acceleration graph described nothing more than
the "jerk" that results as the cart goes from a condition of zero net
force to one where the falling weight provides the net force? I have
had excellent success with the Pasco carts and the motion detectors,
even the "noisy" acceleration graphs make sense to students as they
continue to examine these "imperfect" conditions.
Pat Callahan
Catasauqua HS, PA