Question

QUESTION 7 A person having a mass, m= 75.0 kg, stands on a ladder of mass mi=9.20 kg and length 1=5.50 m. The bottom end of the ladder rests on the floor at a point 3.50 m from the wall. Assume the wall is frictionless but the floor is not and has a 0.435 coefficient of static friction with the ladder's feet. At what critical distance from the bottom end of the ladder would the person stand to cause the ladder to just start sliding down the wall? (Assume that the person's weight is concentrated at the point where she/he steps on the ladder). (10 points) с (= 5.50 m A B d = 3.50 m

Answer 1

mi=9. 9.20kg 4 M= 75 kg 5.50 L Ole mig 3.50=& 3.50 5.so fi COSO = {fy.o 0 - 50.480 N2 = (mitm) g = 84.20g 5 Ni= f = u N2 = (0.435x842x9.8). At point of sliding = 358.94N. Mozo Solving for Cuticals migx coso + mg xr, coso = Nilsino 9.2009.8× S.So Cos 50.48 + 75x9.8 x 81 x Cosso 48 2 358.94 x S.Sox Sin So.u8° ri= 2092 m Aur