$\frac{u}{{u}_{max}}=1-{\left(\frac{2y}{h}\right)}^{2}$

where h is the distance separating the plates and the origin is placed midway between the plates. Consider a flow of water at ${15}^{\circ}C$ , with ${u}_{max}=0.30\frac{m}{sec}$ and $h=0.50\text{}mm$ . Calculate the shear stress on the upper plate and give its direction.