1. Experiment: Pull items of the same weight but different base area with a spring scale over an identic surface - the tractive force will be the same!
实验：同样的重量，但不同的根据地一个弹簧秤同文面拉项目-牵引力将是相同的！
来自互联网
2. Experiment: Pull items of the same weight but different base area with a spring scale over an identic surface - the tractive force will be the same!
