1. Apr 24, 2012

ramly

There is a ladder with mass M that is leaning against a frictionless wall. The coefficient of static friction between the floor and the ladder is say 0.4. What is the max angle that the ladder can make with the vertical before it starts to slide? *the axis of rotation is at the ladder's contact with the floor*

2. Apr 24, 2012

haruspex

Let ladder be at angle θ to vertical.
Let (horizontal) force from wall be H.
Force from floor has horizontal component H, vertical component M.
If coefft friction is λ, max H = λ.M, at which point tan(θ) = 2.λ.

3. Apr 25, 2012

ramly

what did you get as an answer?

4. Apr 25, 2012

Khashishi

is this homework?

5. Apr 25, 2012

ramly

no its not

6. Apr 25, 2012

haruspex

You're asking me to compute atan(2*0.4) for you? OK: 0.67 radians, or 38.7 degrees.
(Note: that's the angle to the vertical.)

7. Apr 26, 2012

kingsly

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Very detailed info.You made some good points there.thank for give us a good answer.