Equation $(4\mathrm{.}25$b$)$ provides a solution for the pressure rise in a pipeline due to rapid valve closure based on Newton's second law. Derive Equation $(4\mathrm{.}21),$ the speed of pressure wave in a pipe, from this equation, Equation $4\mathrm{.}25$b$.$

Equation $4\mathrm{.}21$: C$=\sqrt[\phantom{2}]{\frac{E_c}{p}}$

Equation $4\mathrm{.}25$b: Delta P $=$ p$*$C$*V_o$