- #1
Kennedy
- 70
- 2
Homework Statement
Two masses, A and B, are placed on the edges of a mass of 20 kg which is homogeneously distributed figure such that an unstable equilibrium is achieved. If the mass of A is 12 kg and the mass of B 16 kg, how large is the distance x from the left end of the board to the support point? A) 3 m B) 3.25 m C) 3.4 m D) 3.75 m E) 4 m
Homework Equations
Centre of mass = m1(x1) + (m2)(x2)/(m1 + m2)
The Attempt at a Solution
I attempted this problem but got it wrong, mostly because I don't know what an unstable equilibrium is. I looked it up and it appears to me that any external force that acts on a system with an unstable equilibrium will gravely affect the system. Is this correct? I just went about finding the centre of mass of the system, by doing 12(0) + (16)(6) / (12 + 16) = 3.43 m. So, that was my answer, but it is wrong. I also never used the mass of the board, by I had assumed that since the mass was homogeneously distributed that it wouldn't affect the centre of mass.