The document discusses Newton's three laws of motion. It begins by defining force and describing the different types of forces. It then explains each of Newton's three laws in detail: 1) Law of Inertia, which states that objects at rest stay at rest and objects in motion stay in motion unless acted upon by an unbalanced force. 2) Objects accelerate when a force acts on them, directly proportional to the force and inversely proportional to the mass. 3) For every action there is an equal and opposite reaction - whenever two objects interact, they apply forces to each other that are equal in magnitude but opposite in direction. Examples are provided to illustrate each law.

1. Prepared by: Kayraine Mae E. Caballero, LPT

2. This pit crew member is pushing a race
car forward. Is the race car pushing back
on him? If so, does it push back with the
same magnitude of force or a different
amount?

3.  Is a push or pull exerted by an
object on another or by the
body on the environment.
 Vector quantity that has
magnitude and direction.
FORCE

4. 2 TYPES OF FORCES
CONTACT FORCES
- Force between bodies that are in
direct contact with each other.
1. Normal Force
2. Friction Force
3. Tension Force

5. Normal Force
Exerted on an object by any
surface that it is contacted with.
Perpendicular always to the
surface of contact even t any
angle.

6. Friction Force
Exerted on an object by a
surface, directed parallel to the
surface.

7. Tension Force
Pulling force exerted by a
stretched rope on an object
which it is attached.

8. 2 TYPES OF FORCES
 NON-CONTACT FORCES
- Force that acts even if
interacting bodies are separated
by distance.
1. Gravitational Force
2. Electrostatic force

9. 4 Fundamental
Forces
Gravitational Force
Electromagnetic Force
Strong nuclear Force
Weak Nuclear Force

10. NEWTON’S
3 LAWS OF
MOTION

11. LAW OF INERTIA
What is Inertia?
-The tendency of a body to
resist in the change of state of
motion whether in motion or
motionless.
Newton’s First law of
Motion!

12. - “An object at rest tends to stay at
rest and an object in motion tends
to stay in motion with the same
speed and in the same direction
unless acted upon by a net force.”
Fnet=0
Law of Inertia
Newton’s First Law of Motion

13. Two Clauses and a Condition

14. •Once airborne,
unless acted on by
an unbalanced force
(gravity and air –
fluid friction), it
would never stop!
•Unless acted
upon by an
unbalanced force,
this golf ball
would sit on the
tee forever.

15. Application of Newton’s First Law
Because of inertia, objects (including you) resist
changes in their motion. When the car going 80
km/hour is stopped by the brick wall, your body
keeps moving at 80 m/hour.

16. Newton’s Second Law
Newton's second law of motion can be
formally stated as:
“The acceleration of an object as
produced by a net force is directly
proportional to the magnitude of the
net force, in the same direction as the
net force, and inversely proportional
to the mass of the object.”

17. Newton’s Second Law
THE BIG EQUATION
a = Fnet / m
Fnet = m • a
1 Newton = 1 kg • m/s2

18. Your Turn to Practice
Net Force(N) Mass(kg)
Acceleration(m/
s/s)
1. 10 2
2. 20 2
3. 20 4
4. 2 5
5. 10 1 10
The Fnet = m • a equation is often used in algebraic
problem solving. The table below can be filled by
substituting into the equation and solving for the
unknown quantity. Try it yourself to solve.
If mass remains constant, doubling the acceleration, doubles the force. If force remains
constant, doubling the mass, halves the acceleration.

19. Application of Newton’s Second Law
Think about the situation when you are pushing your bicycle versus when you are
pushing your car. You require more force to be given to the car in order to move
it at an equal acceleration as compared to force required to move your bicycle.
Bicycle having less mass than a motor cycle accelerates at a lesser force applied on
it. Alternatively, if three of your friends help you push the car, you can push the car
easily as compared to you doing it alone. Hence, the mass remained the same but
the increased force provided more acceleration!

20. CHECK YOUR UNDERSTANDING
• 1. What acceleration will result when a 12 N net force
applied to a 3 kg object? A 6 kg object?
• 2. A net force of 16 N causes a mass to accelerate at a
rate of 5 m/s2. Determine the mass.
• 3. How much force is needed to accelerate a 66 kg
skier 1 m/sec/sec?
• 4. What is the force on a 1000 kg elevator that is
freely at 9.8 m/sec/sec?

21. Newton’s Third Law of Motion
“For every action, there is an
equal and opposite reaction.”

22. Newton’s Third Law of Motion
The statement means:
• in every interaction, there is a pair of
forces acting on the two interacting
objects.
• the size of the forces on the first
object equals the size of the force on the
second object.
• the direction of the force on the first
object is opposite to the direction of the
force on the second object.

23. Newton’s Third Law of Motion
According to Newton,
whenever objects A and B
interact with each other, they
exert forces upon each other.
When you sit in your chair,
your body exerts a downward
force on the chair and the
chair exerts an upward force
on your body.

24. Newton’s Third Law of Motion
-a force on the chair
-and a force on your
body.
These two forces are
called action and
reaction forces.

25. Application of Newton’s Third Law
• Consider the propulsion
of a fish through the
water. A fish uses its fins
to push water backwards.
In turn, the water reacts
by pushing the fish
forwards, propelling the
fish through the water.

26. Application of Newton’s Third Law
• Flying gracefully
through the air, birds
depend on Newton’s
third law of motion.
As the birds push
down on the air with
their wings, the air
pushes their wings up
and gives them lift.

27. Other examples of Newton’s Third Law
•The baseball forces
the bat to the left
(an action); the bat
forces the ball to
the right (the
reaction).

28. Other examples of Newton’s Third Law
•A car is equipped
with wheels which
spin backwards. As
the wheels spin
backwards, they
grip the road and
push the road
backwards.

29. Newton’s Laws of Motion
1st Law
- “An object at rest tends to stay at rest and an object in motion
tends to stay in motion with the same speed and in the same
direction unless acted upon by a net force.”
2nd Law
- “The acceleration of an object as produced by a net force is
directly proportional to the magnitude of the net force, in the
same direction as the net force, and inversely proportional to
the mass of the object.”
3rd Law
“For every action, there is an equal and opposite reaction.”

30. THE END!
THANK YOU