近年来出版的某些教辅资料中,常常刊载有如下一道力学估算题,流传甚广,影响颇深,笔者认为原题给出的参考解法与试题的科学性原则不符,存在重要的疏漏,有必要进行深人研讨。例1 跳绳是一种健身运动,设某运动员的质量是50 kg,他一分钟跳绳180次,假定在每次跳跃中,脚 In recent years, some of the supplementary materials published in the journals often contain the following mechanical estimation questions, which are widespread and have a profound impact. The author believes that the reference solutions given in the original questions do not conform to the scientific principles of the questions and there are important omissions. It is necessary to conduct in-depth discussions. Example 1 Rope skipping is a type of fitness exercise. The weight of an athlete is 50 kg. He skips 180 times a minute, assuming that in each jump, the foot