cbse physic chapter 9th class

1. motion

2. What is a motion
• The movement of a body (or object) is called
motion.
• A common characteristic of all the moving
bodies is that they change their position with
time.
• A body is said to be in motion (or moving
when its position changes continuously with
respect to a stationary object taken as
reference point.

3. Stationary
objects
After five
seconds car
reaches here
A moving
car

4. Distance travelled
• The distance travelled by a
body is he actual length of the
path covered by a moving
body irrespective of the
direction in which the body
travels.

5. Displacement
• When a body moves from one
position to another, the shortest
(straight line) distance between
the initial position and final
position of the body, along with
direction, is known as its
displacement.

6. Distance and Displacement
Displacement
4km
3km
• Distance travelled = 5+3= 8km
• Displacement = 4 km towards east.

7. 1. Distance is a scalar quantity
(because it has magnitude only, it
has no specified direction).
2. Displacement is a vector quantity
(because it has magnitude as well as
a direction).

8. • The distance travelled by a moving body
cannot be zero but the final displacement of a
moving body can be zero.
• Example at next slide

9. 4km
3km

10. Made by yash
purohit