Starting from rest, a body slides down a 45 degrees inclined plane in twice the time it takes to slide down the same distance in the absence of friction. The co-efficient of friction
between the body and the inclined plane is? ​

iron would move it is magnetic there is a mag field around the current in the wire

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.