【单选题】6 / 10常深度情形长波满足的波动方程为A∂2ζ∂t2=c2∂2ζ∂x2\frac{\partial^2\zeta}{\partial t^2}=c^2\frac{\partial^2\zeta}{\partial x^2}∂t2∂2ζ=c2∂x2∂2ζ正确B∂ζ∂t=c∂ζ∂x\frac{\partial\zeta}{\partial t}=c\frac{\partial\zeta}{\partial x}∂t∂ζ=c∂x∂ζC∂2ζ∂t2=c2∂2ζ∂z2\frac{\partial^2\zeta}{\partial t^2}=c^2\frac{\partial^2\zeta}{\partial z^2}∂t2∂2ζ=c2∂z2∂2ζD∂ζ∂t=−c\frac{\partial\zeta}{\partial t}=-c∂t∂ζ=−c参考答案A参考解析∂2ζ∂t2=c2∂2ζ∂x2\frac{\partial^2\zeta}{\partial t^2}=c^2\frac{\partial^2\zeta}{\partial x^2}∂t2∂2ζ=c2∂x2∂2ζ(K8−26K8-26K8−26)。