Question

Question 5 In the figure, a uniform plank, with a length L of 4.24 m and a weight of 538 N, rests on the ground and against a frictionless roller at the top of a wall of height h-1.34 m. The plank remains in equilibrium for any value of e 700 or more, but slips i ø 700 Fin ће сое с ent of static roton between the plank and the ground. Roller I. Number Units Attempts:0 of 4 used C Check Answer

Answer 1

Solition,

Horizontal component of force,

Fx = 0

f - N1 sin(theta) = 0

Vertical component of force,

Fy = 0

N2 + N1 cos(theta) - mg = 0

N1(h/sin(theta)) - mg(L/2) cos(theta) = 0

Coefficient of friction, u = [4.24 x (sin70)^2 x cos70] /[2 x 1.34 - 4.24 sin70 (cos70)^2]

u = 0.578

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