VQ The average shear stress is given by T = It Here V is the shear force on the section, I is the moment of inertia of the entire section about the neutral axis, and t is the width of the section at the distance y where the shear stress is being calculated. Q is the product of the area of the section above (or below) y and the distance from the neutral axis to the centroid of that area (Figure 1). In short, Q is the moment of the area about the neutral axis. I y An I-beam has a flange width b = 300 mm, height h = 300 mm, web thickness t = 10 mm, and flange thickness t; = 15 mm. Use the following steps to calculate the shear stress at a point 70 mm above the neutral axis. -b. H Part A - Moment of inertia The shear formula includes the moment of inertia of the whole cross section, I, about the neutral axis. Calculate the moment of inertia. Express your answer with appropriate units to three significant figures. Part B - Q for the given point The shear stress 70 mm above the neutral axis depends on the value of Q for the area above that point. Calculate the value of Q. Express your answer with appropriate units to three significant figures. Part C - Shear stress Use the results from Parts A and B to calculate the shear stress at a point 70 mm above the neutral axis if the shear force on the section is V = 4 kN. Express your answer with appropriate units to three significant figures.