The document defines key concepts in motion including speed, velocity, uniform and non-uniform motion, displacement, scalar and vector quantities, and acceleration. Speed is defined as the distance traveled per unit time, while velocity refers to displacement per unit time and includes both magnitude and direction. A body has uniform speed or velocity if it covers equal distances in equal time intervals, and non-uniform if distances are unequal over equal times. Acceleration is defined as the rate of change of velocity over time.

2. The distanced travelled by an
object in unit time is called speed.

3.  Speed = Distance travelled
Time taken
 Unit of speed = unit of distance
unit of time
= metre
second

4. A body has uniform speed if it
travels equal distances in equal
intervals of time.

5. A body has non-uniform sped if it
travels unequal distances in equal
intervals of time.

6. The measure of the change of
position of an object in a
particular direction is known as
displacement.

7. Vector quantities are those which
need magnitude as well as direction.
 Eg :- displacement, velocity,
acceleration, etc.

8.  Scalar quantities are those which
need only magnitude.
Eg :- distance, speed, time, mass,
volume, etc.

9.  The displacement in unit time is called
velocity.
 Velocity = Displacement
Time
 Unit of velocity = unit of displacement
unit of time
 Unit = metre/second.

10. A body has a uniform velocity if
it travels in a straight line and
moves over equal distances in
equal intervals of time.

11. When a body does not cover
equal in equal intervals of time
the velocity is said to be non-uniform
velocity.

12.  The rate of change of velocity is known as
acceleration.
 Acceleration = change in velocity
Time
= Final velocity – Initial velocity
Time
 a = v – u
t
 Unit of acceleration = meter/(second)2

13.  In certain cases the final velocity
becomes less than the initial
velocity and results in negative
acceleration and is termed as
retardation.