1. The problem statement, all variables and given/known data A particle of mass m moves on the inside surface of a smooth cone whose axis is vertical and whose half-angle is alpha . Find the period of small oscillations about a horizontal circular orbit a distance h above the vertex. 2. Relevant equations Not sure. Lagrangian maybe F = ma The answer is 2pi/tan(alpha) • sqrt(h/(3g)) not sure how to get it though. 3. The attempt at a solution not sure what the question is . Initially i thought it was asking for the period of an oscillation in the vertical axis if disturbed by a small force while in a circular orbit than i thought it might mean what he period for the circular orbit is. I tried using a lagrangian after trying by Newtonian methods.