Abstract: Taking advantage of the PASCO rotational experiment device,the author measured the inertia of a particle through the law of falling bodies.It is found that the falling acceleration a should be the slope of the v-t graph instead of the intercept of a-t graph;and for the same rotation system,the influence of resisting moment on the experiment is eliminated by twice changing the mass m of the hanging object.To reduce the error of resisting moment at the second falling,the smaller the difference Δm is,the more accurate the experimental results will be,and the minimum relative error will reach 0.54%.

Key words: the PASCO rotating experiment device, rotational inertia, falling acceleration, resisting momen