A painter wishes to know whether or not he can safely stand on a ladder. The ladder has a mass M1 = 7.0 kilogram which is uniformly distributed throughout its length L = 7.0 meter. The ladder is propped up at an angle θ =75 degree. The coefficient of static friction between the ground and the ladder is μ = 0.183, and the wall against which the ladder is resting is frictionless.
(a) Determine the maximum mass of the painter for which the ladder will remain stable when he climbs a distance d =4.9 meter up the ladder.
(b) If the painter does not stand on the ladder, find what is the minimum angle θ for which the ladder will remain stable?