费力杠杆:动力臂小于阻力臂,动力大于阻力.费力但是__________.

问题描述:

费力杠杆:动力臂小于阻力臂,动力大于阻力.费力但是__________.

费力杠杆:动力臂小于阻力臂,动力大于阻力.费力但是____省距离______.

动力臂x动力=阻力臂x阻力
ps:任何机械都不省功