关于贵刊2000年第8卷第2期刊登的《走出牛顿第二定律应用中的误区》一文,我认为有一些不妥之处. 1.文中说:加速度取正值说明加速度与合外力方向相同,没有问题.但加速度取了负值,说明加速度与合外力方向相反,这显然违背了牛顿第二定律.这段话显然不对,因为加速度取正值还是取负值都是基于规定,以物体运动 With regard to the article “The Misunderstandings in the Application of Newton’s Second Law,” published in the 8th issue of Volume 2 of your magazine in 2000, I think there are some inconveniences. 1. The text says: Acceleration takes a positive value to indicate the direction of acceleration and external force. In the same way, there is no problem. However, the acceleration has taken a negative value, indicating that the acceleration is in the opposite direction to the external force. This is obviously contrary to Newton’s second law. This is obviously wrong because the positive or negative acceleration is based on the regulations. Object movement