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A uniform ladder 5.0 m long rests against a frictionless, vertical wall with its lower end 3.0 m from the wall. the ladder weighs 160 n. the coefficient of static friction between the foot of the ladder and the ground is 0.40. a man weighing 740 n climbs slowly up the ladder. part a what is the maximum frictional force that the ground can exert on the ladder at its lower end?

Respuesta :

jushmk
If Ff = Frictional force exerted at the ladder's end, then

Ff = Normal force*coefficient of friction

Normal force = Total weight carried by the ladder = 160+740 = 900 N
Coefficient of friction = 0.40

Therefore,
Ff = 0.4*900 = 360 N

Note: Once this force is exceeded, the ladder starts to slide.