Newton's Laws of Motion

secondary school physics

1. Sir Isaac
Newton’s
Three Laws
of Motion

2. "Nature and
Nature's
Laws lay hid
in night;
God said, 'Let
Newton be!' --
And all was
light." (Pope.)
Sir Isaac Newton
1642 - 1727

3. Three Laws of Motion
1. Law of
Inertia
2. Law of
Acceleration
3. Law of
Interaction

4. I. The 1
st
Law
of Motion

5. Law of Inertia
An object at rest will remain at
rest, and an object in motion
will remain in motion with
constant velocity unless acted
upon by an external force.
In other words….

6. a) Balanced and
Unbalanced Forces

9. Click here for better
understanding on Balanced and
Unbalanced Forces.

10. The seat belt provides the unbalanced force which
brings you from a state of motion to a state of rest.
Perhaps you could speculate what would occur
when no seat belt is used.
Click here for better understanding on
Newton’s First Law.

11. If the truck were to abruptly stop and the straps
were no longer functioning, then the ladder in
motion would continue in motion.

12. More on Newton’s First Law

13. II. The 2
nd
Law
of Motion

15. 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.
Law of Acceleration
F
net
= m . a

16. It accelerates in the direction
that you push it.
If you push twice as hard, it
accelerates twice as much.
If it gets twice the mass, it
accelerates half as much.
F
net
= m . a
Click here for better understanding on
Newton’s Second Law.

17. Click on pictures for more problems
on Newton’s Second Law

18. III. The 3rd
Law of Motion

19. Law of Interaction
In every action, there is always
an equal and opposite reaction
Click here for better understanding on Newton’s Third Law.

20. The elephant's feet push backward on the ground; the
ground pushes forward on its feet. The right end of the
right rope pulls leftward on the elephant's body; its body
pulls rightward on the right end of the right rope. The left
end of the right rope pulls rightward on the man; the man
pulls leftward on the left end of the right rope. The right
end of the left rope pulls leftward on the man; the man
pulls rightward on the right end of the left rope. The
tractor pulls leftward on the right end of the left rope; the
left end of the left rope pulls rightward on the tractor. etc.,
etc.

21. Click for more understanding.
up,
up
and
AWA
Y!
Let's study how a
rocket works to
understand
Newton's Third
.Law

22. Summary

23. Thank You Very
Much!!!
Prepared By
Kathleen Joy N. Buot