Aladder is leaning against a vertical wall, and both ends of the ladder are at the point of slipping. the coefficient of friction between the ladder and the horizontal surface is μ₁ = 0.115 and the coefficient of friction between the ladder and the wall is μ₂ = 0.103. determine the maximum angle with the vertical the ladder can make without falling on the ground.

Consider a production line with five stations. station 1 can produce a unit in 9 minutes. station 2 can produce a unit in 10 minutes. station 3 has two identical machines, each of which can process a unit in 12 minutes (each unit only needs to be processed on one of the two machines. station 4 can produce a unit in 5 minutes. station 5 can produce a unit in 8 minutes. which station is the bottleneck station?