It takes less effort to lift a piano with a pulley. If the piano is lifted 3 meters, then... Select one:
a. the pulley rope is pulled 1 meter.
b. the pulley rope is pulled more than 1 meter, but less than 3 meters.
c. the pulley rope is pulled 3 meters.
d. the pulley rope is pulled more than 3 meters.

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.

its c i just checked it

dang that balls went far