3. There are two states of anThere are two states of an
object :-object :-
• Rest stateRest state
•Motion stateMotion state
4. Rest state
If the position of an
object is not changing
with time , then that
object is in rest motion .
5. Motion state
If the position of an
object changes with time,
then that object is in
motion state .
6. Scalar Quantities
• The physical quantities which
requires only magnitude to
describe them and there is no need
to direction are known as scalar
quantities .
• Examples :- Distance , speed ,
time , volume , area , density ,
temperature , pressure , etc. .
7. Vector Quantities
• The quantities which require
direction as well as magnitude
to describe them are known as
Vector Quantities.
• Example :- Displacement ,
velocity , acceleration , force ,
etc. .
8. Distance
The length of actual path
travelled by an object is
known as distance covered
by the object .
It is a scalar quantity .
9. Displacement
The shortest distance
travelled between initial
position to final position is
known as Displacement .
It is a vector quantity .
10. Speed
Speed of a body is the
distance travelled by it per
unit time .
Speed = distance travelled
time taken
It is a scalar quantity .
Its unit is m/s .
11. Velocity
Velocity of a body is the
distance travelled by it per
unit time in a given direction.
It is a vector quantity .
Velocity = displacement/time
Its unit is m/sec .
12. Acceleration
The rate of change of velocity
of an moving object is known
as its Acceleration .
It is a vector quantity .
a = final velocity – initial V.
time taken
Its unit is m/s sq. .
13. Retardation
The rate of decreasing
of velocity of a moving
object is known as
retardation .
It is a vector quantity.
14. Uniform acceleration motion
A kind of motion in which
velocity of an object
increases in equal amount
in equal time interval
is known as uniform
accelerated motion .