First pressure derivative of bulk modulus at zero pressure

1. Nov 29, 2013

sirwan

what is the physical meaning of first pressure derivative of bulk modulus at zero pressure. if it is ∂k/∂p, i say how it change with pressure, if it is at zero pressure?

2. Nov 29, 2013

DrDu

It means $\partial k/\partial p|_{p=0}=\im_{\Delta p \to 0}(k(0+\Delta p)-k(0))/\Delta p$
I.e. it is the change of bulk modulus when you increase the pressure slightly starting at p=0.
This is analogous to asking about the accelleration of a car dv/dt at zero speed.