URL：https://media.cheggcdn.com/study/aa1/aa135f16-5821-46a7-867e-88d494344261/image.jpg
掲載元：https://www.chegg.com/homework-help/questions-and-answers/slendar-bar-p-r-rests-hemispherical-disc-radius-53-mathrm-~cm-point-q--end-p-moves-horizon-q115587553
