October 14, 2011

GENERAL CONDITIONS FOR EQUILIBRIUM IN A PLANE

 

  If the forces shown in the diagram act on a body, that body will be in equilibrium only if both resultant force and the resultant are zero.

 

 

If the forces shown in the diagram act on a body, that body will be in equilibrium only if both resultant force and the resultant are zero.

 

 

 

 

 

 

 

 

 

 

 

Now the forces acting on the object are not parallel so that resultant force has components in the directions of both Ox and Oy.

Therefore, if the object is to be in equilibrium the sum of the components in each of the directions Ox and Oy must be zero.

So now we can give the general conditions necessary for an object to be in equilibrium under the action of a set of non-parallel coplanar forces, i.e.

The resultant force in the direction Ox s zero

The resultant in the direction Oy is zero

The resultant moment about any axis is zero

Appling these conditions to a particular problem gives three equations, so there unknown quantities can be found

In some problems it is more convenient to use an alternative set of three independent equation, i.e.

The resultant in the direction Ox ( or Oy but not both ) is zero

The resultant moment about a particular axis is zero

The resultant moment about a different axis is also zero

 

GENERAL CONDITIONS FOR EQUILIBRIUM IN A PLANE

 

 

 

 

 

 

 

 

 

 

Now the forces acting on the object are not parallel so that resultant force has components in the directions of both Ox and Oy.

Therefore, if the object is to be in equilibrium the sum of the components in each of the directions Ox and Oy must be zeIf the forces shown in the diagram act on a body, that body will be in equilibrium only if both resultant force and the resultant are zero.

 

 

 

 

 

 

 

 

 

 

 

Now the forces acting on the object are not parallel so that resultant force has components in the directions of both Ox and Oy.

Therefore, if the object is to be in equilibrium the sum of the components in each of the directions Ox and Oy must be zero.

So now we can give the general conditions necessary for an object to be in equilibrium under the action of a set of non-parallel coplanar forces, i.e.

ro.

So now we can give the general conditions necessary for an object to be in equilibrium under the action of a set of non-parallel coplanar forces, i.e.

No comments: