A coil spring is stretched by two equal and opposite forces F=120N. The wire diameter is 5 mm and the mean coil diameter is 40 mm. Draw a free body diagram of the spring cut near the point A and identify the internal forces and moments transmitted across the cut. Hence determine the magnitude and location of the maximum shear stress at the cut. Assume that the shear force V causes a uniform shear stress V/A, where A is the cross-sectional area.