find the magnitude and direction of the resultant of two vectors u and v with magnitudes of 6 and 2 and an angle of 140 between them.
i got |u+v|=7.64 units and the direction to be 9.69 deg, is it right?
You can make a sketch, and complete the parallelogram of forces.
From this, the magnitude of the resultant forces is given by the cosine rule, taking the sides 6 and 2 and the angle (180-140) = 40 degrees.
$\displaystyle Resultant = \sqrt{2^2 + 6^2 - 2(2)(6)\cos(40)}$
Can you try out again on the direction now?