In the "4p" nuclear fusion reaction 4 nuclei of hydrogen (i. e. 4 protons) fuse into 1 nucleus of helium, emitting energy. describe qualitatively (i. e. in words) the reaction: how is it possible to overcome the electric repulsive force? what is the nuclear force? how is the energy generated?

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.

no. dot product   =0 when vecs at right angles

force tends to be low and long diustance masses are high

not too sure thinking all accelerations are pointed down