1. Newton’s Laws of Motion

2. I did NOT “create” the laws of motion! I merely identified them!
Isaac Newton
There are “laws” that govern the motion of objects in the universe.
Isaac Newton was the scientist who identified gravity the laws of motion.
I did NOT “create” the laws of motion!
I merely identified them!

3. Newton found 3 laws of motion that are true throughout the universe.
Newton’s First Law of Motion:
Objects at rest will remain at rest, and objects in motion will remain in motion, unless an unbalanced force acts on them.

4. Something makes them move faster or slower.
The 1st Law of Motion
In OTHER words…
Objects that are sitting still will stay still, and…
Objects that are moving will keep moving until…
Something makes them move faster or slower.

5. Newton’s 1st law can be described with one word: inertia.
Definition: inertia – the tendency of an object at rest to remain at rest OR
the tendency of a moving object to keep moving.

6. If you were in outer space, and you threw a baseball…what would happen to it?
It would keep moving in a straight line forever!
At least, until an unbalanced force acted on it…

7. Mass is a measure of inertia.
Inertia describe an object’s resistance to change motion.
Which would be more difficult to push?

8. Inertia increases as mass increases.
Even if the two vehicles are moving at the same speed, the truck would be more difficult to stop because it has more inertia.

9. Newton’s 2nd Law Newton’s Second Law: F = ma
The unbalanced force acting on an object equals the object’s mass times its acceleration.
F = ma
Definition: Newton – the SI unit used to measure force or weight.
Weight is also a measure of force.

10. From Newton’s 2nd Law, we can infer that…
As an object’s mass increases, it takes more force to change its acceleration.
Which would you rather play tennis with?
Which is easier to accelerate?

11. Forces are so common that we take many of them for granted.
Every push, pull, and any other movement is related to Newton’s Laws of Motion.
Understanding force is especially important to automobile manufactures.

12. Why is Force important?
An understanding of forces is also important in every sport…

13. Lets cut to the chase…what is Newton’s 3rd Law?
The 3rd Law of Motion
Lets cut to the chase…what is Newton’s 3rd Law?
Newton’s 3rd Law states:
For every action force, there is an equal and opposite reaction force.
In order for Newton's law to be true, there must always be more than one force present.

14. The 3rd Law of Motion
Forces come in pairs that act on different objects.
When you kick a soccer ball, you exert a force on the ball, and it does the same on your foot.
The soccer ball is exerting the same amount of force on the man’s foot. He can feel the ball exerting the force!

15. The 3rd Law of Motion
If forces are equal & opposite, why don’t they cancel out?
In a force pair, each force acts on a different object.
The force on one object may be enough to accelerate it…
But that same force may not be enough to accelerate the other object.

16. The reaction force is acting on the foot.
In the force pair below, the action force is acting on the soccer ball.
The reaction force is acting on the foot.
The forces don’t cancel because they aren’t acting on the same object!
6 N
6 N

17. Momentum
A small car and an 18-wheeler are traveling beside each other at the same speed.
If both vehicles brake at the same time with the same amount of brake force, which one will stop first?
The small car, of course. This is because it has less momentum.

18. (Mass x Velocity) Momentum
Definition: momentum – the amount of motion an object contains.
Momentum is measured by multiplying the mass of the object by the velocity or speed of the object.
(Mass x Velocity)

19. Momentum
An unbalanced force is needed to change the momentum off a moving object.

20. Momentum Conservation!
The Law of Conservation of Momentum states:
The momentum of a moving object is never destroyed – it is transferred.

21. Momentum Conservation
Momentum is transferred!
When a moving object hits another object…
The momentum of the moving object is transferred to the other object.

22. Momentum Conservation!