The cross section of a 3-m-long steel bar is an equilateral triangle with 50-mm sides. T...

The cross section of a 3-m-long steel bar is an equilateral triangle with 50-mm sides. The bar is subjected to end twisting couples causing a maximum shearing stress equal to two-thirds of the elastic strength in shear . Using Table 6.2, determine the angle of twist between the ends. Let G=80 GPa.