This document discusses the different types of friction: Static friction is the friction between two stationary surfaces in contact. Sliding friction is weaker and acts when surfaces slide over each other. Rolling friction is even weaker and occurs when objects roll over a surface. Fluid friction is the resistance caused when a fluid (gas or liquid) flows past a solid surface or another fluid. Streamlined shapes help reduce fluid friction by decreasing drag.

1. TYPESOF
FRICTION
DONE BY :- NIRANJANA
CLASS:- 8A

2. FRICTION
 Friction is a contact force.
 Friction opposes the relative motion between the surfaces.
 Unit of Friction - Netwon.
 Friction is caused by the irregularties on the two surfaces in contact.
 Friction always acts in a direction opposite to the motion.
 When the roughness of the surface increases friction increases.

3. TYPESOFFRICTON
Types of friction are:
Static friction
Sliding friction
Rolling friction
Fluid friction

4. STATICFRICTION
01

5. STATICFRICTION
Static force is the
friction applied
between a stationary
object and the surface
on which it is resting.

6. EXAMPLES
A table lamp
resting on a light
table.
A box of much
weight against the
ground, difficult to
lift and move.
A car park on a
hills.

7. SLIDILINGFRICTION 02

8. SLIDINGFRICTION
 Sliding friction is friction that
acts on objects when they
are sliding over a surface.
 Sliding friction is weaker
than static friction.

9. EXAMPLES
When you write
with a pencil on
paper
A box being slid
across the floor
A child sliding
down through a
slide in a park.
Rubbing both the
hands together to
create heat.
02
01 03 04

10. 03 ROLLINGFRICTION

11. Rolling friction is friction that acts on
object when they are rolling over a
surface.
Rolling friction is weaker than sliding
friciton.
ROLLINGFRICTION

12. EXAMPLES
Pulling a
luggage fitted
with rollers.
Skateboard
moving on
wheels
Kicking a
football is a
rolling
friction.
01 03
02

13. FLUID
FRICTION 04

14. FLUIDFRICTION
 When a fluid is in contact with soild
object or another fluid object, the
force resist the motion between them
is called fluid fricition.
 Gases and liquid are both fluids.
 Streamlined shape help to reduce
fluid fricition.

15. Look carefully at the shape of an aeroplane.
Do you find any similarity in its shapes and
that of a bird??
Questiontime??
A- They have a streamlined shape to
decrease drag ( the frictional force exerted
by fluids is also called drag).