There are two loudspeakers (S1, S2) set at the same volume and playing the same tone. Speaker S1 is 5.0 m away from you, while Speaker S2 is 2.5 m away from you. At your location, the sound emitted by S2 will have: (a) twice the intensity of the sound from S1.
(b) three times the intensity of the sound from S1.
(c) four times the intensity of the sound from S1.
(d) the same intensity as the sound from S1.
(e) approximately zero intensity.

gravity

explanation:

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.