Maths M1-Help Needed!!

[ashutoshamatya]

The diagram shows a small metal ball, of mass 2 kg, resting in the horizontal groove between two smooth planes inclined at 20 and 40 degrees to the horizontal. find the magnitude of the contact forces P and Q.

 

[hassam]

first find out all the angles on the diagram...........then apply lami's theorem which is nothing more than a restatement of sine rule and applies for three coplanar forces in equilibrium as in this case......
2g/sin 60=p/sin140=q/sin160
http://en.wikipedia.org/wiki/Lami's_theorem