Part A Given water's dipole moment of 6.17×10−30C⋅m6.17×10−30C·m, what's the energy change when a water molecule, with its dipole moment initially opposite a 3.52-kN/CkN/C electric field, swings to align with the field?

f=ma newton's second law 7x8=56n

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.