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AP® Physics C: Mechanics

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Static Equilibrium: A Leaning Ladder

APPHMC-K7S8RB

A ladder of mass $m$ and length $L$ leans against a frictionless wall making an angle of 60° with the ground.

If the ladder is initially motionless, what is the minimum coefficient of friction, $\mu$, between the ladder and the ground that will keep the ladder from sliding down?

A

$\cfrac {1} {2}$

B

$\cfrac { 1 }{ 2 } \sin { 30^{\circ} }$

C

$\cfrac { 1 }{ 2 } \cos { 30^{\circ} }$

D

$\cfrac { 1 }{ 2 } \tan { 60^{\circ} }$

E

$\cfrac { 1 }{ 2 } \tan { 30^{\circ} }$