First law of motion

1. FORCE ANDLAWSOF
MOTION
FIRST LAW OF MOTION

3. An object in motion
• Galileo studied on the motion of object that

4. An object in motion...
• If the right-side plane were ultimately made
horizontal (that is, the slope is reduced to zero), the
marble would continue to travel forever trying to
reach the same height that it was released from.

5. An object in rest
A stationary object will remain in rest until
an external force is acted on it.
These objects
will not move
unless an
external
force act on
it.

6. Inertia
• If an object is at rest it tends to
remain at rest; if it is moving it
tends to keep moving. This
property of an object is called its
inertia.
• The resistance an object has to a
change in its state of motion.

7. SIR ISSAC NEWTON
• Galileo’s theory was
further studied by
Newton. And he
formulated three laws of
motion.

8. First law of motion
The first law of motion is stated as:
An object remains in a state of
rest or of uniform motion in a
straight line unless compelled to
change that state by an applied
force. This is also called as LAW OF
INERTIA

10. Some examples
When force is applied to the card, why the
coin falls inside the glass?

11. And now the answer
 This is due to the INERTIA of the coin.
 At first both the coin and the card are in rest.
 Then an external force is applied only to the
card not to the coin.
 So the coin which in rest is remains in rest
due to inertia. Thatswhy the coin falls inside
the glass.

12. Some examples
An astronaut in
outer space
away from
gravitational or
frictional forces
throws a rock.
The rock will…..

13. And now the answer
The rock will continue
to move in a straight line at
a constant speed.
The rock’s tendency to
do this is called INERTIA.

15. Application to everyday life
 Opening a bottle
 Removing dusts from cloths
 Seat belts
 Seismometer