设地球质量为M则GM/R^2=g0,设在高度为h的山上重力加速度为g1则GM/(R+h）^2=g1则g1=g0R^2/(R+h)^2则f=1/T=1/(2∏√(L/g1)=1/(2∏)√[g0R^2/L(R+h)^2]