- The forces and their directions are described in figure-1.
- We can solve the problem in many ways.
- In this solution we used the method of dividing the forces into horizontal and vertical components.
"The components of " F_3 " are :"The components of F3 are :
F_("3x")=F_3*cos(30)=50sqrt (3). sqrt(3)/2=(50.3)/2=150/2=75NF3x=F3⋅cos(30)=50√3.√32=50.32=1502=75N
F_("3y")=F_3.sin(30)=50sqrt(3)*1/2=25sqrt(3)N F3y=F3.sin(30)=50√3⋅12=25√3N
"The components of " F_1 " are :"The components of F1 are :
F_("1x")=F_1*cos(0)=100.1=100NF1x=F1⋅cos(0)=100.1=100N
F_("1y")=F_1.sin(0)=100.0=0NF1y=F1.sin(0)=100.0=0N
"The components of " F_2 " are :"The components of F2 are :
F_("2x")=F_2*cos(30)=100sqrt (3). sqrt(3)/2=(100.3)/2=300/2=150NF2x=F2⋅cos(30)=100√3.√32=100.32=3002=150N
F_("2y")=-F_2.sin(30)=100sqrt(3)*1/2=-50sqrt(3)N F2y=−F2.sin(30)=100√3⋅12=−50√3N
- Figure-5 shows the vector sum of the horizontal components of the forces.
Sigma F_("x")=F_("1x")+F_("2x")+F_("3x")
Sigma F_("x")=100+150+75=325N
- Figure-6 shows the vector sum of the vertical components of the forces.
Sigma F_("y")=F_("1y")+F_("2y")+F_("3y")
Sigma F_("y")=0-50sqrt(3)+25sqrt(3)=-25sqrt(3)N
- Figure 7 shows the resultant vector and direction.
F_r=sqrt((Sigma F_x)^2+(Sigma F_y)^2)
F_r=sqrt((325)^2+(-sqrt(25))^2)
F_r=sqrt(105625+625)
F_r=325.96N
- We must specify the angle of the resultant vector.
tan theta=(Sigma F_y) / (Sigma F_x)
tan theta=-(25sqrt(3))/325=-(sqrt(3))/13=-0.13323468
theta=-7.59^o