1. FRICTION ON INCLINED PLANE AND LADDER FRICTION

2. CIVIL ENGINEERING DEPARTMENT MGITER,NAVSARI.
B.E. – II, SEM- III
PRESENTED BY: group 8
SR.NO.
NAME
ENROLLMENT NO. 1
BAGHEL POOJA R. 2
CHAVHAN TRUSHNA H. 3
DESMUKH DIVYA G. 4
PARMAR HINA M.
GUIDED BY:-
PREETI VARMA
CIVIL ENGINEERING DEPARTMENT MGITER,NAVSARI.

3. Contents:
FRICTION ON INCLINED PLANE
LADDER FRICTION

4. Friction on inclined planes
If a particle of mass m kg rests on an inclined plane of angle θ°, the forces acting will be:
Normal Reaction R θ
Friction Fr
Friction
Weight = mg
Weight
Normal Reaction
To solve problems involving inclined planes, it is easier to resolve parallel and perpendicular to the plane.

6. When the particle is just on the point of slipping:-
Resultant force is zero θ Fr R mg i j
In limiting equilibrium

7. So the coefficient of friction is dependent only on the angle of the slope.
If we know the angle at which the particle just starts to slip, we can use this to calculate the coefficient of friction.
This is particularly useful when modelling as we can do a simple experiment to estimate a value for μ.

8. Particle just on point of slipping so
EXAMPLE :
A block of mass 3kg is placed on a rough horizontal table. The table is gradually tilted until the particle begins to slip. The block is on the point of slipping when the table is inclined at an angle of 41o to the horizontal. Find the coefficient of friction.
41o 3g R Fr
Particle just on point of slipping so

9. Find the magnitude of the friction force on the particle.
EXAMPLE:
A particle of mass 10kg is at rest on a rough plane inclined at 30o to the horizontal. A horizontal force of magnitude 10N acts on the particle.
Find the magnitude of the friction force on the particle.
The coefficient of friction between the particle and the slope is m. Find an inequality that m must satisfy.
30o
10g N R Fr
10N

10. (a)
(b)
The friction inequality states

11. The ladder is a device for climbing or scaling on the roofs or walls.
LADDER FRICTION:-
The ladder is a device for climbing or scaling on the roofs or walls.
It is made of wood or iron.

12. There are two long pieces in the ladder to which many small cross pieces called rugs are connected at equal distances to work as steps.
The necessary and sufficient conditions of equilibrium for the ladder are:
ΣFx =0
              Σ Fy =0
               Σ Mi =0
                                                                                 
                     
                                                          
Ladder friction

13. FORCES ACTING ON THE LADDER
WL = Self weight of ladder through c.g. of ladder
Wm = Weight of man standing on ladder
Rf = Reaction by the floor on the ladder
Ff = Friction force between ladder and floor
Rw = Reaction by wall on the ladder
Fw = Friction force between ladder and wall.

14. As the upper end of the ladder tends to slip downwards, therefore friction force between wall and ladder will be upwards.
Similarly, as the lower end of the ladder tends to slip away from the wall, therefore the force of friction between floor and ladder will be towards the wall.

15. THANK YOU