Find the resultant force in each case:

a) Forces 33N and 47 N acting at a point at an angle of 40 degree to each other.

b)A third force is acting on the point at an angle of 140 degree to the resultant force in part a.

a) F₁ = 33 , F₂ = 47

resultant = R = [F₁²+F₂² +2F₁F₂COS@]^1/2

@ is the angle bw F₁ & F₂

@ is 40 , so cos@ = 0.72 approx

plugging all these values we get

R = 73N approx

b) here @ is 140 so cos140 = cos(180-40)

                                        =-cos40 = -0.72

resultant = R = [33² +47²-2x0.72x33x47]^1/2

                   = 34N approx