FOR Masters of pharmacy (pharmaceutics)

1. EVALUATION SEMINAR ON
EFFECT OF FRICTION
PREPARED BY:
MALAY PAUL
1ST SEM. M. PHARMA
DEPARTMENT OF
PHARMACEUTICS
SUBMITTED TO:
PROF. H.S.
KEERTHY
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2. CONTENTS:
-
 INTRODUCTION
 FACTORS THAT AFFECT FRICTION
 TYPES OF FRICTION
 EFFECT OF FRICTION
 ADVANTAGES OF FRICTION
 DISADVANTAGES OF FRICTION
 METHODS FOR INCREASING AND DECREASING FRICTION
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3. FRICTION
[INTRODUCTION]
• FRICTION IS A FORCE THAT OPPOSES THE RELATIVE MOTION
BETWEEN TWO SURFACES OF OBJECTS IN CONTACT.
• THE FORCE OF FRICTION ALWAYS ACTS IN A DIRECTION OPPOSITE
TO THAT OF THE APPLIED FORCE.
• FORCE THAT SLOWS DOWN OR STOPS MOTION.
 FRICTION IS LESSER ON A SMOOTH, SHINY SURFACE.
 FRICTION IS GREATER ON A ROUGH SURFACE.
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4. FACTORS THAT AFFECT
FRICTION
• ROUGHNESS OF THE SURFACE
• THE EXTENT TO WHICH THE TWO SURFACES PRESS
TOGETHER
• NATURE OF THE SURFACE
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5. HOW FRICTION AFFECTS MOTION?
IF YOU ROLL A BALL ALONG THE FLOOR OR GROUND, IT
WILL SLOW DOWN AND STOP EVEN THOUGH NO APPARENT
FORCE IS BEING APPLIED TO IT. THE BALL SLOWS DOWN
AND STOPS BECAUSE OF FRICTION.
FRICTION SLOWS DOWN A MOVING OBJECT. FRICTION
OCCURS WHEN TWO OBJECTS RUB AGAINST EACH OTHER.
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A car that runs on a very rough road slows
down due to friction. However, on a smooth road,
it travels fast.
A smooth surface has a very few bumps and
hollows. There is less friction on a smooth
surface. A running object can glide or move
continuously with very little force.

8. TYPES OF FRICTION:-
There are four types of friction
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9. Definition-
Static friction:-when a force is applied to
an object but it does not cause it to move
.
example: pushing on a wall
Fluid friction:-occurs when a object
moves through a fluid, meaning either a
liquid or gas.
examples: skydiving, swimming
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10. Sliding friction:-The frictional force which resists
the real relative sliding motion between two contact surfaces
is known as sliding or friction.
example:-Rubbing both hands together to create heat
Rolling friction:-The force resisting the motion of a
rolling body on a surface is known as Rolling friction or
Rolling resistance.
Example :- Car moving on wheels 10/1
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11. Effects of Friction:-
Friction produces heat.
Friction causes wear and tear.
Friction opposes motion
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12. COEFFICIENT OF FRICTION
"IT IS DEFINED AS THE RATIO OF THE LIMITING
FRICTION FORCE TO THE NORMAL REACTION FORCE".
- IT IS REPRESENTED BY THE “ . –
- IT IS GIVEN BY -> = F / FN
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µ
µ

13. Advantages of Friction:-
Friction between pen and paper enables
us to write on the paper.
Friction between our feet and the ground
allows our movements like standing,
walking and running
Friction between the surface of the road
and tyres of our vehicles allow the vehicles
to move without slipping
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14. Disadvantages of Friction :-
Friction causes moving objects to stop or
slow down.
Friction produces heat causing wastage of
energy in machines
Friction causes wear and tear of moving
parts of macinery, soles of shoes, etc
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15. Ways of reducing friction:-
Smoothing out Surface ex. Applying floor wax
and scrubbing the floor.
Placing a slippery substances between two solid
surfaces
ex. Grease, oil and other lubricating liquids
Using rotating object
ex. Roller bearings,
ball bearings and wheels
Streamlining vehicles to reduce friction caused
by air.
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16. Ways to increase friction:-
New materials with more bumps and
hollows are produce for making car brakes
lining.
New styles for the soles of athletes’ shoes.
Its aim is for runners to run with greater
speed.
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17. REFERENCES
:-
• ARTICLE OF HOW SURFACE ROUGHNESS AFFECTS FRICTION: BY BY DR. PRIYOM
BOSE, PH.D
• REGULAR ARTICLE OF EFFECT OF FRICTION: BY ALI HEIDARI, MOHAMMAD
REZA FOROUZAN, SALEH AKBARZADEH
• STUDIES AND RESEARCH ON FRICTION, FRICTION FACTOR AND AFFECTING
FACTORS : A REVIEW (IJESRT JOURNAL)
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19. IMPORTANT QUESTIONS:-
1. WRITE THE WAYS TO INCREASE AND REDUCE
FRICTION?
2. DEFINE FRICTION . WRITE ADVANTAGES AND
DISADVANTAGES OF FRICTION.
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