What do understand by the efficiency of a machine? By using a block and tackel a man can raise a load of 720 N by an effort of 180 N. Find the mechanical advantage of the method.

Efficiency of a machine is how well the machine works and what the machine is capable of doing.

Mechanical advantage=Load/Effort.

720/180=4

the box does not move because you need to use a force greater than 300 n. you are only using 50 n. it needs to at least be 301 n for the box to move because then it is an unbalanced force and it will move the way that the greater force is pushing it. if you use only 300 n it will be a balanced force and will not move because the force you are exerting on the   box is the same as its force.

hope this !

im sorry if i went too in depth, i am going to include a link to a video on khan academy that will explain this.   hope that you like the video and that it explains more in detail to you.

that is the link.

where’s the list ? the question is incomplete