Sage-Tips

What are the conditions of equilibrium of coplanar forces?

The Coplanar Forces in Equilibrium The sum of forces must be zero. The sum of the moments of the forces about a point in the anticlockwise direction is equal to the sum of the moments of the forces about the same point in the clockwise direction.

In which case Lamis theorem is not valid?

The Sine Rule is only applicable for triangles and not for all polygons. Therefore, Lami’s Theorem is only applicable to three forces, but not for ‘n’ number of forces.

Is Lamis theorem applicable for concurrent forces?

Solution: First of all, Lami’s Theorem is applicable only in the case of coplanar concurrent forces. Secondly, it is applicable to planes as well as 3D objects. It means option B fails to satisfy the condition. There should be three concurrent forces acting at a point, so option A is invalid.

When three coplanar non parallel forces are in equilibrium then it should be?

concurrent
If a body is in equilibrium under the action of three non-parallel coplanar forces, the forces must be concurrent, that is, must meet at a single point.

What is equilibrium equation for coplanar force system?

The equation of the equilibrium force line is therefore y = −x − 1. 5s. As is evident by inspection, the system has no net torque with respect to any point on this line, and a force equal to −F = 2i−2j acting at any point of the line will suffice to bring the system into equilibrium.

What are different methods of studying the equilibrium of coplanar forces?

The method is to find the one force, called the resultant, which is equal to the sum of the original forces, and then to balance this resultant with an equal and opposite force, called the equilibrant. The resultant of the original forces is found by the method of vector addition.

What is Lamis Theorem?

Lami’s theorem states that if three forces acting at a point are in equilibrium, then each of the force is directly proportional to the sine of the angle between the remaining two forces.

What is the limitations for applying Lamis Theorem?

Limitations of Lami’s theorem There should be only three forces acting on the object. If there are more than three forces or less than three forces, we may not apply the Lami’s theorem. Lami’s theorem is applicable to only coplanar, concurrent and non-collinear forces.

What is non-parallel coplanar forces?

A concurrent coplanar force system is a system of two or more forces whose lines of action ALL intersect at a common point. The last illustration is of a non-concurrent and non-parallel system. This consists of a number of vectors that do not meet at a single point and none of them are parallel.

What is coplanar non-concurrent forces?

The forces whose line of action lie on the same plane but they do not meet at one point are known as coplanar non-concurrent forces.