第一题你是对的第二题错了。弹簧每个点的速度不一样的，小虫只是相对当时所在速度为1cm/s（注意，不是1m/s).

speed converge to v1+v2It can be proved (you can check my answers in "第二题：条件足够了"). Ok, I get your meaning. You are trying to discretize the problem using time slice of 1 sec, right? You can use this kind of method, although it makes problem unnecessary complex (remember not to fix the time slice, you should calculate the limit when time slice approach 0). I use this approach as well, of course, for computer programming, and the time slice is usually set to sufficiently small value to get accuracy answer. The cause of the problem is that you set the time slice to 1 sec. During this 1 sec period, the worm moves some not negligible distance already. Using time slice of 1, the worm speed: .01 * ( 1 + 1/n + 1/n*(n-1) + 1/ n*(n-1)*(n-2) ... ) < .01 * ( 1 + 1/n + 1/n + ... ) = .02 I.e. the method itself poses a problematic constraint on the problem. Try set the time slice smaller.

speed converge to v1+v2It can be proved (you can check my answers in "第二题：条件足够了"). Ok, I get your meaning. You are trying to discretize the problem using time slice of 1 sec, right? You can use this kind of method, although it makes problem unnecessary complex (remember not to fix the time slice, you should calculate the limit when time slice approach 0). I use this approach as well, of course, for computer programming, and the time slice is usually set to sufficiently small value to get accuracy answer. The cause of the problem is that you set the time slice to 1 sec. During this 1 sec period, the worm moves some not negligible distance already. Using time slice of 1, the worm speed: .01 * ( 1 + 1/n + 1/n*(n-1) + 1/ n*(n-1)*(n-2) ... ) < .01 * ( 1 + 1/n + 1/n + ... ) = .02 I.e. the method itself poses a problematic constraint on the problem. Try set the time slice smaller.

第一题，正方形的话爬了1米，正三角形的话是2/3第二题，我在想，既然小虫相对弹簧的速度恒定是1，是不是时间就是1，距离就是2呢？

so any hint to Q1?

老兄你在乱猜是吧1D里面没有曲线。