Lami's theorem and forces?

Question

In lami's theorem,What does "three equilibrium forces" means?
Why this theorem for three forces?Why not for "4,5 or another number" of forces?

Answer 1

There are 3 forces F1, F2 and F3 working in the same plane on one object. It does not move.
Suppose the vector F1 + vector F2 = vector F(result),
then vector F(result) + vector F3 = 0 or
vector F(result) = -vector F3.
In this story does not fit another number of vectors.
When more forces work keep themselves in balance, you have to add as vectors different pair until you have three left.
Th

Answer 2

Lami's theorem in statics states that if three coplanar forces are acting on a same point and keep it stationary, then it obeys the relation where A, B and C are the magnitude of forces acting at the point (say P), and the values of α, β and γ are the angles directly opposite to the forces C, B and A respectively. Lami's theorem is applied in static analysis of mechanical and structural systems. See also Mathematics of Vectors Vectors in Mechanics TextBook 'Engineering Mechanics' by Beer & Johnson TextBook 'Physics' by Hayt & Kemmerly

Answer 3

The sum of the forces at a junction is zero.
If you consider a beam and you load the beeam with n diferent weights on the beam you can support that two points , the rules would be the same. the beam lets say two point. The forces at that point are called reaction. the reations support all the forces on the beam.This follows Newton's third law. The beam is now in equilibrium.

Answer 4

consider 3 forces,the resultant of each force is the sin of the angle between other two forces.