Maths M1 Help Needed!! please~~

[alevel4a]

can some1 explain how to do this kind of question?
as detailed as possible.
thank you so much~

 

[hassam]

since the particle is in equilibrium we cn do some resolving......sum of forces in x direction must be 0 as do the sum in y direction since the particle is not moving........
R(>)12P cos (alpha) - 5P sin (alpha) = 0
SOLVING THIS WE GET

tan alpha=12/5
alpha = arctan (12/5) ~ 67.4 deg to 1d.p

resolving in the y direction we get
5P COS (alpha) + 12P sin (alpha) = 2.6*g
substitute ur anser to (i) for alpha
on solving for P we get P =( g/5)~ 2n