How can I find the initial case of kinetic energy

INITIAL CASE OF KINETIC ENERGY CAN BE FOUND BY

(KE)INITIAL = (KE)FINAL - F*D*COS (ALPHA)

Explanation:

The object in stationary position when comes to motion due to some force is called energy.

The kinetic energy of an object depends on its velocity. To change its velocity, one must exert a force on it. It turns out there's a connection between the force one applies to an object and the resulting change in its kinetic energy.

The equation to find kinetic energy, KE, is the following, where m is mass and v is velocity:

K.E = 1/2 * m * v

KE(final) - KE(initial)  =  (force) (distance)

KE(final) - KE(initial)  =  Work done on object

Another way to write this is with vectors F for force and d for displacement. Then

    KE(final) - KE(initial)  =   F  (dot product)  d

                                       =   F * d * cos(alpha)

where alpha is the angle between vector F and vector d.

i think they are all correct

explanation:

they seem good

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.