聰明筋斗丸
將一,二粒筋斗丸放在透明膠盒中, 把膠盒向各方向傾斜, 筋斗丸就翩起筋斗來, 十分好看, 筋斗丸在外國很早就引起物理教師的興趣, 有關文章曾多次見諸The Physics Teacher 等刊物. 其動作包含多種力學知識. 它的構造簡單, 在筋斗丸內裝了一顆小鋼珠. 當底面傾斜時, 鋼珠在丸內下滾, 撞出丸的下圓壁給它一個沖力F, 如圓圖. 使筋斗丸翻了一個筋斗.
Item no : JHL 674 pk of 10 nos

BOUNDING Bean
Bean can rotate vertically on hand or incline plane, it seems very clever.
Due to a small steel bead inside the bean, so the force apply to the wall of bean is changing and rotating.
Size of bean is equal to pill
Item no : JHL 674 pk of 10 nos