vikas askiitian expert
Last Activity: 13 Years ago
for this we have to consider a horizontal & vertical axis or x & y axis ...
tension can have 2 components , Tcos@ & Tsin@ ....
for left string tension has 2 components T2cosB along horizontal & T2sinB along verticle upward ...
for ryt string components are T1cos@ along horizontal & T1sin@ along verticle upward ...
now , at this stage we have to balance all the forces since we know that body is in equilibrium so no net force
exists in any direction ...
for upward direction , net force = T1sin@ + T2sinB
for downward dirctn , net force is weight of body = mg
for verticle equilibrium net force along verticle direction is 0 ..
Tsin@ + TsinB = mg .......................1
for horizontal direction , T1cos@ = T2sinB ...........2 (net force 0)
now solve 1 & 2 get the desired result
one more method can be used for all systems which are in equilibrium ,
lami's theorem =>
the Lami's theorem is an equation relating the magnitudes of three coplanar, concurrent and non-collinear forces, which keeps an object in static equilibrium, with the angles directly opposite to the corresponding forces. According to the theorem,

- where A, B and C are the magnitudes of three coplanar, concurrent and non-collinear forces, which keeps the object in static equilibrium, and
- α, β and γ are the angles directly opposite to the forces A, B and C respectively.

Lami's theorem is applied in static analysis of mechanical and structural systems.