So, just like the other problem,

和之前的问题一样
I'm not asking you to find v and h.

我并没有让你们找出 v 和 h
So the trick, once more,

所以再强调一次诀窍是
is to jump straight to the torque equation.

直接跳到力矩方程
Forget about the force equation.

别去想力的方程
Go to the torque equation and take the torque around this point,

直接用力矩方程算出这个点上的力矩
then this guy is out.

这家伙就没用了
No matter what's going on--

无论怎样
doesn't matter -- the torque due to the pivot is out.

都不牵扯到通过支点的力矩
So, we have to equate the torque due to the force I apply

所以就要让外力产生的力矩
to the torque due to gravity pulling the rod down.

和向下拉这根杆的重力力矩相等
Torque due to force I apply;

外力的力矩