Determine the minimum force P to prevent a 30kg rod AB from sliding on a wall. The contact surface at B is smooth, whereas the coefficient of static friction between the rod and the wall at A is Us=0.2. The rod is diognal on the wall from bottom left (B), with the force P applied at B towards the right, to top right (A). It is 4 m across and 3 m up. Making the rod 5 m long.