1. Why should I wear my seatbelt?
Newton’s Laws
Why
should I
wear my
seatbelt?

2. What do you think about seatbelts?
Use your clicker to take the Seatbelt Survey.
Answer honestly, we just want to know current views about seatbelts.

3. Seatbelts and Newton’s Laws
Understanding Newton’s Laws helps us understand the importance of seatbelts.
Let’s get started…

4. Newton’s 1st Law of Motion
What does it say?
An object in motion tends to stay in motion with a constant velocity and an object at rest tends to stay at rest unless acted upon by a net force.
So what does that mean?...

5. Newton’s 1st Law of Motion
It means…
An object will tend to keep doing what it’s doing unless a force makes it do something else (speed up or slow down).
This is called inertia – the tendency of an object to maintain its current state of motion.

6. How does this show Newton’s 1st Law?

7. Newton’s 1st Law of Motion
This law is also known as The Law of Inertia.
Watch the demos!

8. One last thing about the 1st Law…
Don’t try this one on the test…

9. Newton’s 2nd Law of Motion
What does it say?
The acceleration of an object is directly proportional to the net external force acting on the object and inversely proportional to the mass of the object.
So what does that mean?

10. Newton’s 2nd Law of Motion
That means…
If force is increased, acceleration will increase
(directly proportional)
If mass is increased, acceleration will decrease
(inversely proportional)

11. Newton’s 2nd Law of Motion
So how could I relate Force, Mass, and Acceleration at the same time?
In a mathematical equation of course!
F = m * a
Force
in Newtons (N)
Acceleration
in meters / sec
(m/s)
Mass
in Kilograms (kg)

12. Newton’s 2nd Law of Motion
If the same force is applied to both the ball and the wall, which will have the greater acceleration?? Why?

13. Newton’s 3rd Law of Motion
What does it say?
For every action there’s an equal but opposite reaction
So what does that mean?

14. Newton’s 3rd Law of Motion
It means…
Forces exist in pairs called ‘action-reaction’ pairs.
When a bat applies a force to a ball, the ball applies an equal but opposite force on the bat.

15. Newton’s Law and a Car Crash
When in a car crash, there are 3 collisions:
Your car with the other object.
Your body with the car.
Your organs with the inside of your body.
Can you relate this to all 3 laws?

16. The Importance of Seat Belts
Do the following as you read the article:
Find 3 places where the 1st law is illustrated. Highlight them and label them 1A, 1B, and 1C.
Find 3 places where the 2nd law is illustrated. Highlight them and label them 2A, 2B, and 2C.
Find 3 places where the 3rd law is illustrated. Highlight them and label them 3A, 3B, and 3C.

17. The Importance of Seat Belts
After you read the article:
Make an advertisement or bumper sticker that advocates wearing your seat belt. These will be hung in the hall…so make sure all content is appropriate.
On a separate sheet of paper, answer the following:
Relate your ad/bumper sticker to all 3 of Newton’s Laws.
Explain if your view of wearing seatbelts has changed. Explain.
Use Newton’s Laws to describe how YOU not wearing your seat belt or having unrestrained items in your car could harm your passengers.