Friction is the force that opposes the relative motion between two objects in contact. It arises due to intermolecular forces between the two surfaces. Friction allows us to walk without slipping and enables cars to move forward on roads. However, it also leads to disadvantages like wear and tear of brakes and shoes over time. Engineers try to reduce friction in machines using methods like lubrication and bearings while also increasing friction in areas like car brakes where it is needed.

1. 1

2. Made by :-
UsmAN RajpOot

3. 3

4.  What is friction ?
 Advantages of Friction
 Disadvantages of friction
4

5. Friction (frictional force) is a
force that acts in a opposite
direction to movement.
The force which always
opposes the motion of one
object over another, object in
contact with it , is called
friction.
5

6. 6

7.  It is because of the friction
between the sole of the shoe and
ground prevents us from slipping.
 While walking , we push the
ground backwards and the force
of friction acts in the opposite
direction (i.e. in the forward
direction) and prevents us from
slipping. By making the balance.
7

8. 8

9.  Walking on slippery ground is difficult because
friction on slippery ground is less due to
which we may slip.
9

10.  It is because of the friction
between the tyres of car and
the road which enables car to
move forward without
skidding.
 If there were no friction , car
would stay where it was.
10

12.  It becomes sometimes difficult to drive and
control car on wet road.
 This is because of water present on road
reduces friction.
12

13.  It is because of the friction between the tip of
the pencil ( or pen) and paper.
 Carbon particles from the pencil lead rubs off
from it, due to the friction, which appears as
black marks on the paper.
13

14.  We can hold a glass tumbler in our hands
because of friction between the tumbler and
our hands.
 Similarly, we can pick up the books laying on
the desk by our hands.
14

15.  Friction also produces heat.
 We rub matchstick against the rough side of a
matchbox, then friction between both of them
produces heat and this heat burns chemicals
present at the head of matchstick and it lights
up.
15

16. 16

17.  When we walk on the road, tiny surfaces of the
shoe keep on breaking off slowly due to which
the soles of our shoes wear out slowly
 Due to which shoes get damaged and becomes
unfit to wear.
17

18. After Before18

19.  Like the shoe tiny particles of tyres also
breakdown due to friction when they run on
road.
 The same thing also happens with the bicycles
19

20. Before After 20

21.  Brake pad is made of rubber
 When the brakes of the vehicles are applied a
lot of friction is produced
 Friction wears out the brake pads gradually
Before - After
21

22.  The friction between the soles of
the shoes and wear away hard
stone steps slowly.
 Such type of staircase are usually
seen at :
 Railway station
 Old Buildings
22

24.  Friction reduces the motion of moving parts of
a machine . In fact all the moving things such
as (cars , buses, airplanes, boats, ships ,etc.) are
slowed down by friction.
24

25. 25

26.  New materials with more bumps and hollows
are produce for making car brakes lining.

27.  New styles for the soles of athletes’ shoes. Its
aim is for runners to run with greater speed.

28.  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

29.  Using rotating objects
ex. Roller bearings, ball bearings and
wheels

30. 30

31. 31