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AP® Physics 1 & 2

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Static Systems: Calculating Forces

APPH12-HMHK1N

A ladder is leaning against a wall at an angle $\theta$ from the horizontal as in the diagram below. The ladder has wheels at the top to prevent accidental damage to the wall.

Created by Chris Lyke for Albert.io. Copyright 2016.

If the mass of the ladder is $m$ and its length is $l$, what is the magnitude of the force of friction between the ladder and the floor?

A

$mg\times\cos(\theta )$

B

$mgl\times\cos(\theta)$

C

$\dfrac { mg }{ 2 }\sin(\theta )$

D

$\dfrac { mg }{ 2 }\cot(\theta )$