- #1
Karol
- 1,380
- 22
Homework Statement
The flat piece is between 2 walls and is pushed eccentrically by force F. what should be the relation between the width x and the height y in order to achieve self locking (that the piece won't go down)?
Homework Equations
Friction Force: f=μN
Balance of moments: F1L1=F2L2
The Attempt at a Solution
I make 2 equations of moments around the contact points with the walls. the friction coefficient is μ. round point A:
$$F\left(\frac{x}{2}-l\right)+yR_2=\mu R_1\rightarrow R_2=\frac{F\left(\frac{x}{2}-l\right)}{\mu x-y}$$
round point B:
$$F\left(\frac{x}{2}+l\right)=yR_1+\mu xR_1\rightarrow R_1=\frac{F\left(\frac{x}{2}+l\right)}{y+\mu x}$$
First i see that R1≠R2, is it true?
I now insert R1 and R2 in the forces equation with the inequality ##F\geq\mu(R_1+R_2)## and get:
$$\frac{2}{\mu}\geq (x-2l)(\mu x+y)+(x+2l)(\mu x-y)$$
I can't get a conclusion from that. where, in which book, is this subject covered? i feel i complicated it