The composite beam is constructed from wood and reinforced with a steel strap. Use the method of Sec. 6.6 and calculate the maximum shear stress in the beam when it is subjected to a shear of $V=50 \mathrm{kN}$. Take $E_{\mathrm{st}}=200 \mathrm{GPa}$ $E_{\mathrm{w}}=15 \mathrm{GPa}$