In this question use g=9.8g = 9.8g=9.8 m s−2^{-2}−2.
A uniform rod AB AB\,AB of length 3 m and mass 8 kg is suspended in horizontal equilibrium by two vertical light inextensible strings attached to the rod at C C\,C and at DDD, where AC=0.6AC = 0.6AC=0.6 m and DB=0.9DB = 0.9DB=0.9 m.
A particle of mass m m\,m kg is attached to the rod at AAA.
Show that the tension in the string at D D\,D is (4.8−0.4m)g(4.8 - 0.4m)g(4.8−0.4m)g newtons.
Hence find the greatest value of m m\,m for which the rod can remain in equilibrium in this position.
56 exam-style questions on CCEA A Level Maths 4.2 Moments (A-level only), covering 4.2.1 Moments (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.