Question

urgent answer please two forces each 4N act on the opposite side of a 0.4m square plate. calculate the resultant force and couple acting on the plate

Answer 1

1) Resultant force:
The two forces have same magnitude (4 N) but opposite verse, so their resultant is zero:
$R=4 N + (-4 N)= 0 N$

2) Couple
The two forces have opposite direction and they are applied at a distance d=0.2 m from the center of the square, so they generate a couple equal to the sum of the torques generated by each force:
$\tau= F_1 d_1 + F_2 d_2 = (4 N)(0.2 m)+(4N)(0.2 m)=1.6 N m$