How do u get mass when u have 24 newtons of force at 4m/s2

Use the formula from Newton's 2nd law of motion:

Force = (mass) · (acceleration)

Fill in the numbers that you know:

24 N = (mass) · (4 m /s²)

Divide each side by (4 m/s²) :

Mass = (24N) / (4 m/s²)

Mass = 6 kg

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.

f=ma newton

f=100x2.5=250n