Three forces acting on a body are represented by the sides of equilateral triangle in same order then.

Question

A. the forces are equal

B.the resultant of force is zero

C.the resultant of force is non-zero

D.the body moves with non uniform acceleration.

Answer 1

In graphical solutions, you add vectors tip to tail meaning if you want the sum of vector 1 plus vector 2, you draw vector 1 with its tail at the origin. Then from the tip of vector 1, draw vector 2 with its tail at the tip of vector 1. The sum is the arrow from the origin to the tip of vector 2.

If three forces are present you draw the first vector. Then at the end of that, draw the second. At the end of the second, now draw the third. The sum would then be from the tail of the first to the tip of the third.

In this problem, since the three vectors make a triangle, the tip of the third is at the same position as the tail of the first. Therefore, the sum is a vector with length equal to zero, which means that the sum of all three is zero => answer a. I’m not sure how answer a is different from answer b, so that would also be correct. For there to be a net force, the forces cannot make a closed shape in a diagram.

Answer 2

If I interpret the question correctly, all three forces have the same magnitude, but are not "equal" because they are in different directions.

Combining the three gives only a torque and so the body simply rotates with a constant angular acceleration.

I choose the C answer. BUT: if they are looking only for magnitude, it would be A