This document defines and explains key concepts related to motion including distance, displacement, speed, velocity, acceleration, and instantaneous speed. It provides formulas for calculating average speed, acceleration, and defines positive and negative acceleration. Examples are given to demonstrate calculating average speed from total distance and time. The document concludes by reminding the reader to practice problems from the notes and previewing that graphs will be covered in the next class.

1. MOTION-
SPEED,
VELOCITY
&
ACCELERATION

2. D
C
E
A
B
DISTANCE AND DISPLACEMENT
Here Distance is the total path length ABCDE and
Displacement is the length of straight line AE
directed along A to E

4. Speed of an object is defined as the distance
travelled by the object per unit time.
SI Unit: Meter/second
Symbol of Representation: m/s or ms-1
Speed = Distance/Time

5. SPEEDOMETER

6. Instantaneous speed The magnitude of speed at a particular
instance of time is called Instantaneous Speed .

8. For Example:
If an object travels 10m in 3 seconds and 12m in 7
seconds. Then its average speed would be:
Total distance travelled = 10 m + 12 m = 22m
Total Time taken = 3s + 7s = 10s
Average speed = 22/10 = 2.2 m/s

12. Acceleration - The rate of change of velocity
per unit time is called Acceleration.
Acceleration is a vector quantity
Acceleration = Change in velocity/ Time taken
SI Unit: m/s2
Types of acceleration:
Positive acceleration: The direction of acceleration is the same if the
velocity is increasing in the same direction. Such acceleration is
called Positive Acceleration.
Negative acceleration: The direction of acceleration becomes opposite
as that of velocity if velocity is decreasing in a direction. Such acceleration
is called Negative Acceleration.
Synonyms of negative acceleration:
1. De-acceleration
2. Retardation

14. NOTE
• Memorize the various formulae done today.
• Solve the numerical problems on your note
book specifying the date and heading clearly
• While you solve the problem, firstly write the
given information.
• Secondly write the formula and then solve.
• Show proper calculation.
• Use SI UNITS while solving problems.

15. IN OUR NEXT CLASS
WE SHALL WORK
WITH GRAPHS