The ISO 2787-1984(E)Annex C pruvides a furmula to calculate the impact energy be-tween two striking reds. However,the formula does not indicate its applying condition , where bothcross-sectional areas shall be equal.

• 对ISO2787－1984（E）附录C中冲击能公式的修正樊发兴，黄跃平（东南大学数学力学系，南京210018）国际标准ISO2787－1984（E）对风动工具性能测定方法作出了规定。