At sea level, density of air = \(1.225\,kg/{m^3}\).The maximum velocity for a lifting flow over a circular cylinder occurs at top surface of the cylinder, where \(\theta \) equals to \({90^ \circ }\).\[{V_\theta } =  – 2{V_\infty }\sin \theta  – \frac{\tau }{{2\pi R}}\]\[ \Rightarrow \tau  =  – 2\pi R\left( {{V_\theta } + 2{V_\infty }} \right)\]\({V_\theta }\) is negative in clockwise direction and \(‘\tau ‘\) is positive, according to sign conventions.Therefore, \[\tau  =  – 2\pi R\left( {{V_\theta } + 2{V_\infty }} \right) =  – 2\pi \left( {0.4} \right)\left[ { – 80 + 2\left( {35} \right)} \right]\]\[\tau  =  – 2\pi \left( {0.4} \right)\left[ { – 10} \right]\]\[\tau  = 25.133\,{m^2}/s\]Therefore, lift per unit span is \[{L^\prime} = {\rho _\infty }{V_\infty }\tau \]\[{L^\prime} = 1.225 \times 35 \times 25.133\]\[ = 1077.577\,N/m\]