| Exam Board | CAIE |
| Module | FP2 (Further Pure Mathematics 2) |
| Year | 2011 |
| Session | June |
| Topic | Moments |
3
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The diagram shows two uniform rods \(B A\) and \(A C\), smoothly hinged at \(A\). The rod \(B A\) has length \(8 a\) and weight \(W\); the rod \(A C\) has length \(6 a\) and weight \(2 W\). The rods are in equilibrium in a vertical plane with \(B\) and \(C\) resting on a rough horizontal floor and angle \(C A B\) equal to \(90 ^ { \circ }\). Show that the normal contact force at \(B\) is \(\frac { 26 } { 25 } W\).
The coefficient of friction between each rod and the floor is \(\mu\). Find the least possible value of \(\mu\).