A thin plate with width $2w=150mm$ and thickness $B=1\mathrm{.}5mm$ is made of Ti$-6$Al$-4$V annealed titanium alloy with properties Yield stregnth $790$ MPa $,$ Tensile Strength $860$ MPa $.$ It has a fracture toughness $Kc=100$MPa$\sqrt[\phantom{2}]{m},$ Estimate the highest load, P$,$ that can be applied without causing sudden fracture when a cnetral crack grows to a length of $25$ mm $.$

Center cack: $,K_3=Y{o}_O\sqrt[\phantom{2}]{a}$

$Y=1+0\mathrm{.}256(\frac{a}{W})-1\mathrm{.}152(\frac{a}{W}{)}^2+12200(\frac{a}{W}{)}^3$