For every action there is an equal and opposite reaction. what does this quote mean?

so it is said that every action has equal and opposite reaction

Explanation:

This is newton's III law which states that if some force is applied in the form of action force to an object then the same magnitude force is applied by the object on the source in reverse direction

so we can say that the reaction force is always applied by object in opposite direction

so in vector form we can say

so it is said that every action has equal and opposite reaction

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.

if the person is shown to have +90n, then ans is -10n.

if the person is shown to have -90n, then ans is +10n.