滑轮的原理和杠杆是一样的``````
一般的,我们把定滑轮看成一个等力杠杆````把动滑轮看成一个省力杠杆``
定滑轮的支点就是转轴,所以动力臂等于阻力臂,由于要拉动一端的物体,另一端就需要出一个等同的力,所以动力也就等于阻力,所以定滑轮是一个等力杠杆；动滑轮的支点在绳子固定端与滑轮相切的点,因此拉力的力臂是重物重力力臂的2倍（当绳子竖直向上拉时）,所以是省力杠杆.
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