Atraveling electromagnetic wave in a vacuum has an electric field amplitude of 81.1 v/m. calculate the intensity s of this wave. then, determine the amount of energy u that flows through the area of 0.0253 m^2 over an interval of 19.9 s, assuming that the area is perpendicular to the direction of wave propagation.

U = 4.39 J

Explanation:

Electric field energy stored in the medium or vacuum is given as

here we know that

E = 81.1 V/m

V = volume

now from above formula we have

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.