Moment

Professor André Pereira

Problem I

• The force F = 600i + 300j - 600k N acts at the

end of the beam. Determine the moment of

the force about point A.

Problem II

• A force F having a magnitude of F = 100N acts along

the diagonal of the parallelepiped. Determine the

moment of F about point A.

Problem III

• A 20N horizontal force is applied perpendicular to

handle of the socket wrench. Determine the

magnitude and the coordinate direction angles of the

moment created by this force about point O.

Moment of a force about specified

axis

Problem IV• Determine the moment Ma produced by the

forces F = 300N, which tends to rotate the rod

about the AB axis.

Problem V• The chain AB exerts a force of 20lb on the door at B.

Determine the magnitude of moment of this force along the

hinged axis x of the door.

Moment of a couple

Problem VI

• Determine the couple moment acting on the

pipe. Segment AB is directed 30° below the x-y

plane.

Problem VII• Express the moment of the couple acting on the pipe

assembly in cartesian vector form. Determine the

moment of each about point O. Take F = {25k}N.

Problem VIII

• Determine the distance d between A and B so that

the resultant couple moment has a magnitude of Mr

= 20 N.m.

Simplification of a force and couple

system

Problem IX• The plate is subjected to four parallel forces.

Determine the magnitude and direction of a

resultant force equivalent to the given force system

and locate its point of application on the slab. F₁ =

40k N and F₂ = 30kN.

Forças r F r x F

Problem X

• The plate is subjected to four parallel forces.

Determine the magnitude and direction of a

resultant force equivalent to the given force system

and locate its point of application on the slab.

Forças r F r x F

References

• Mechanics for Enginners - Statics - Beer and

Johnston – Four Edition.