mechanics ladder problem

[rustic anvil]

Please can someone help me with this question. I don’t understand how to form an equation if friction is acting upwards (F2)

[smoky tide]

is this fm?

[rustic anvil]

No

<@&791435371564892232>

[abstract fable]

F is still Mir

Mu * R

Except the R is Rb

Wait nvm you did that part fine

Take moments about the bottom left

Then wxcostheta is equal to

2xRbsintheta+ 2xF2costheta

They both act in an anti-clockwise direction from the pivot being the bottom left as u can see

And then it’s just using the perpendicular distances

Make it equal to clockwise moment which is Js weight

[rustic anvil]

how did you get the 2xF2costheta bit? I don’t understand 😫😫

THANK YOU SOO MUCH BTW

[crimson minnow]

Shouldn't it Rb instead of f2?

[rustic anvil]

well I got the right answer using f2 but idk where they got 2xF2costheta from 😔

[abstract fable]

yo

soz i was on the bus

[abstract fable]

no

one force is F2

one force is Rb

[abstract fable]

it came from

lemme look

the perpendiculat distance to t he force

of F2

which is

the horizontal line at the bottom

which has a length of 2x cos theta

[crimson minnow]

Thx

[abstract fable]

np