The magnetic field 40.0 cm away from a long, straight wire carrying current 2.00 a is 1.00 mt. (a) at what distance is it 0.100 mt? (b) what if? at one instant, the two conductors in a long household extension cord carry equal 2.00-a currents in opposite directions. the two wires are 3.00 mm apart. find the magnetic field 40.0 cm away from the middle of the straight cord, in the plane of the two wires. (c) at what distance is it one-tenth as large? (d) the center wire in a coaxial cable carries current 2.00 a in one direction, and the sheath around it carries current 2.00 a in the opposite direction. what magnetic field does the cable create at points outside the cable?

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.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west