A second circular drumhead is cut from a different membrane

PHYSICS · Multi-part · Fermi University Physics · Mathematical Methods for Physics · Partial differential equations and boundary-value problems · Special functions and orthogonal polynomials

Conditions of Validity, Ch Separation of variables as a chain of Sturm-Liouville problems

Problem

A second circular drumhead is cut from a different membrane, radius a=0.12 ma=0.12\,\mathrm m and wave speed c=140 m s−1c=140\,\mathrm{m\,s^{-1}}, clamped at its rim and plucked into the same shallow-cone shape as the worked example, f(r)=h(1−r/a)f(r)=h(1-r/a), but raised only h=8.0 mmh=8.0\,\mathrm{mm} at the centre. ((a)) Find the mode frequencies f0,1f_{0,1}, f1,1f_{1,1} and f0,2f_{0,2}. ((b)) Find the first three coefficients c1c_1, c2c_2, c3c_3 of the cone in the mode basis, and say whether they depend on the new radius aa.

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