An object is acted by 3 coplanar forces:30 newton to the north, 20 in the direction S20degrees E and 25 newton in a direction W20degrees S.Find the resultant

1 answer

S20DegE = 290Deg CCW.
W20DegS = 200Deg CCW.

X = hor. = 25cos200 + 20cos290,
X = -23.49 + 6.84 = -16.65N.

Y = ver. = 30 + 25sin200 + 20sin290,
Y = 30 - 8.55 - 18.79 = 2.66N.

tanA = Y/X = 2.66/-16.65 = -0.1596,
A=-9.07Deg = -9.07 +180 = 170.9Deg,Q2.

R = X/cosA = -16.65 / cos170.9 = 16.9N.
@ 170.9Deg.