A uniform ladder of mass M and length L stands on rough horizontal ground and leans against a smooth vertical wall with which it makes an angle ?. A man of mass m stands on the ladder a distance x from the bottom.
(a) Obtain expressions for the normal reaction and the friction force acting at the point of contact between the ladder and the ground.
(b) If the coefficient of friction at this point is 1/3, show that only if tan? < 6/17 is the man able to reach the top of the ladder without it slipping. Use M = 10kg, m = 80kg and L = 4m.