2.5m 4m 2.5 m Figure 2 A pole AB has length 2.5 m and weight 70N. The pole rests with end B against a rough vertical wall. One end of a cable of length 4m is attached to the pole at A. The other end of the cable is attached to the wall at the point C. The point C is vertically above B and BC = 2.5 m. The angle between the cable and the wall is a, as shown in Figure 2. The pole is in a vertical plane perpendicular to the wall. The cable is modelled as a light inextensible string and the pole is modelled as a uniform rod. Given that tana (a) show that the tension in the cable is 56N. Given also that the pole is in limiting equilibrium, (b) find the coefficient of friction between the pole and the wall.

2.5m 4m 2.5 m Figure 2 A pole AB has length 2.5 m and weight 70N. The pole rests with end B against a rough vertical wall. One end of a cable of length 4m is attached to the pole at A. The other end of the cable is attached to the wall at the point C. The point C is vertically above B and BC = 2.5 m. The angle between the cable and the wall is a, as shown in Figure 2. The pole is in a vertical plane perpendicular to the wall. The cable is modelled as a light inextensible string and the pole is modelled as a uniform rod. Given that tana (a) show that the tension in the cable is 56N. Given also that the pole is in limiting equilibrium, (b) find the coefficient of friction between the pole and the wall.