More net torque then, means the door starts moving faster on its hinges.

因此，净扭矩越大， 门在铰链上的移动速度越快。

In other words, the net torques must be equal to zero.

也就是说，净扭矩必须为零。

The net torque on an object is equal to its angular acceleration, times what's known as its moment of inertia.

物体上的合成扭矩等于它的加速度 角撞击称为惯性矩。

And we know that both of those torques equal each other, because the net torque on the ladder is zero.

我们知道这两个时刻是相等的，因为结果 施加在梯子上的扭矩为零。