We know the moon circulates the Earth. Suppose the mass of the Earth and moon are 5.9742 x1024 kg and 7.36 x 1022 kg, whereas the radius of the orbit is 382171 km. What will the gravitational force between the Earth and the moon?

The gravitational force between two objects, one of mass M1 and the other of mass M2, is:

F = G*M1*M2/R^2

Where G is a constant:

G = 6.6x10^11 m^3*/(kg*s^2)

And R is the distance between the two objects.

M1 = 5.9742x10^24 kg

M2 = 7.36x10^22 kg

R = 382171 km = 382171000 m

Then the gravitational force is:

F = 6.6x10^-11 m^3*/(kg*s^2)*(5.9742x10^24 kg)*(7.36x10^22 kg)/(382171000 m)^2

F = 1.987x10^20 N

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.