Find the angular frequency of small oscillations of the block of mass m in the arrangement shown. Neglect the mass of the rod; the system is in a vertical plane.

Question

G1 Physics · Accepted Answer

A displacement of the central block produces twice the end displacement at the left lever arm, so k₃ is reflected as 4k₃. This is in series with k₂, giving kₛ=4k₂k₃/(k₂+4k₃). It acts in parallel with k₁. Hence ω=√{[k₁+4k₂k₃/(k₂+4k₃)]/m}. Correct answer: A.