Answer:
option C
Explanation:
given,
force act on west = 20 lb
force act at 45° east of north = 80 lb
magnitude of force = ?
∑ F y = 80 cos 45⁰
F y = 56.57 lb
magnitude of forces in x- direction
∑ F x = -20 + 80 sin 45⁰
= 36.57 lb
net force
F = [tex]\sqrt{F_x^2+F_y^2}[/tex]
F = [tex]\sqrt{56.57^2+36.57^2}[/tex]
F = 67.36 lb≅ 67 lb
hence, the correct answer is option C