The magnetic field of an electromagnetic (em) plane wave in free space is represented by bb�⃗(zz, tt) = bb0(xx� + (ii/2)yy�)eeii(−ωωωω) where ii = √−1. (a) in what direction is the em wave propagating? what is its propagation speed and its wavelength λλ in terms of the constants given above? [2pts] (b) sketch (the real part of) bb�⃗ in the xy plane at kz = π/2 at quarter-period intervals, at the times t = 0, t/4, t/2 and 3t/4 (where t is the period of the wave). this wave is called an elliptically polarized wave, why? [1pt] (c) calculate the corresponding electric field ee�⃗ and sketch it at the four times specified in part (b). [1pt] (d) find the poynting vector ss⃗ and calculate the power density s carried by the wave. [1pt] (e) the em wave passes through a thin plate of special material which delays the x- component of the magnetic field bx by a phase π/2, so that bx is represented by bb0eeii(−ωωωω+ππ/2) . the y-component of the magnetic field in unaffected. calculate ee�⃗ and sketch ee�⃗ and bb�⃗ at quarter-period intervals, as in parts (b) and (c). [1pt]

i need the answer to this too but idk it ; -;

the entire statement is true and correct.  

there's no diagram, nothing is illustrated, and no question is asked.

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.

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards