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lichenguy

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A uniform beam of length L and mass m is inclined at an angle θ to the horizontal. Its upper end

is connected to a wall by a rope, and its lower end rests on a rough, horizontal

surface. The coefficient of static friction between the beam and surface is μ

Assume that the angle θ is such that the friction force is at its maximum value.

a) Draw a force diagram for the beam.

b) Using the condition of rotational equilibrium, find an expression for the tension T in the rope in terms of m, g and θ.

c) obtain an expression for μ

e) What happens if the ladder is lifted upward and its base is placed back on the ground slightly to the left of its former position? Explain.

I did a, b, and c, but I'm not sure on e. The graph shows μ in terms of the angle θ.

For e i wrote, so far, that F

If I'm understanding this right, μ

Also, I'm not sure what is meant by "Assume that the angle θ is such that the friction force is at its maximum value.".

is connected to a wall by a rope, and its lower end rests on a rough, horizontal

surface. The coefficient of static friction between the beam and surface is μ

_{s}.Assume that the angle θ is such that the friction force is at its maximum value.

a) Draw a force diagram for the beam.

b) Using the condition of rotational equilibrium, find an expression for the tension T in the rope in terms of m, g and θ.

c) obtain an expression for μ

_{s}, involving only the angle θ.e) What happens if the ladder is lifted upward and its base is placed back on the ground slightly to the left of its former position? Explain.

I did a, b, and c, but I'm not sure on e. The graph shows μ in terms of the angle θ.

For e i wrote, so far, that F

_{N}would decrease because F_{T}would now have a component in the same direction as F_{N}.If I'm understanding this right, μ

_{s}is changing to maintain the equilibrium?Also, I'm not sure what is meant by "Assume that the angle θ is such that the friction force is at its maximum value.".

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