在这
![](http://forum.eduzhixin.com/uploadfiles/20160819/1471616640f3ccdd27d2000e3f9255a7e3e2c48800.jpg)
v[t] = (P (1 + ProductLog[-(e^(-1 - (f^2 t)/(m P) + 1. (1. + 1. Log[0.367879 P]))/P)]))/f
v'[0]=0,有空解,取v'[0]=0.0000000001,得v[t]
两种情况的图像
![](http://forum.eduzhixin.com/uploadfiles/20160820/1471658514156005c5baf40ff51a327f1c34f2975b.jpg)
函数:
![](http://forum.eduzhixin.com/uploadfiles/20160820/1471658957156005c5baf40ff51a327f1c34f2975b.jpg)