1. Lesson 5: Newton’s Second Law
EQOD: How much force do you need to move objects of different masses?

2. Initial Thoughts:
Which has more mass: a ping pong ball or a golf ball? Explain
If hit with equal forces, which ball will move farther?
Try it!

3. Evidence I:
What will happen if you hit a ping pong ball with a stick compared to hitting a golf ball with the same stick at the same speed?
Conduct an experiment!

4. Evidence I: Constant Force
1) Place a ping-pong ball in front of the wooden ruler.
2) Carefully bend the ruler back and release it.
3) Record your observations
4) Place a golf ball in front of the wooden ruler.
5) Carefully bend the ruler back and release it. Be sure to bend the ruler back to the same spot (force needs to be constant).
6) Record your observations.
Try to have the ruler hit the balls with the same force!

5. Evidence I: Constant Acceleration
1) Place a ping-pong ball in front of the wooden ruler.
2) Carefully bend the ruler back and release it.
3) Record your observations
4) Place a golf ball in front of the wooden ruler.
5) Carefully bend the ruler back and release it. Be sure to bend the ruler back to achieve the same acceleration as the ping-pong ball (acceleration needs to be constant).
6) Record your observations.
Try and have the ruler hit both balls at the same speed!

7. Which ball moved away from the stick faster?
Evidence I:
What did you discover?
Which ball moved away from the stick faster?
Why?

8. Force= Mass X Acceleration
Evidence II:
Newton’s Second Law states that the amount of force an object is experiencing is equal to the mass of the object multiplied by its acceleration (how fast it is moving).
Force= Mass X Acceleration

9. F= 3kg Mass X 1m/s Acceleration 3N Force= 3kg Mass X 1m/s Acceleration
Evidence II:
If you have two of the three from the equation, you can figure out the last number.
If the mass equals 3kG and the acceleration equals 1m/s, then the force equals 3N (Newtons).
F= 3kg Mass X 1m/s Acceleration 3N Force= 3kg Mass X 1m/s Acceleration

10. Evidence II:
If the force is 6N, and the mass is 2kG, what is the acceleration?
6N Force= 2kG Mass X ?m/s Acceleration
6N/2kG= 3
The acceleration must be 3 m/s.

11. Evidence II: Force: the amount of energy acting upon an object
Mass: the amount of matter (stuff) in an object
Acceleration: A change in the speed or direction of an object

12. Think about it this way:
Evidence II:
So if an object has more mass, then it needs more force to help it accelerate. Otherwise it won’t be able to move.
Think about it this way:

13. Analysis:
What is the mass of an object if it’s force= 16N and it’s acceleration= 8 m/s?
Explain why it might be a good idea for a baseball player to use a bigger bat?
Do you think a person could produce enough force to stop a 2,500 kG car moving 22 m/s? (Hint: calculate force of the car)

14. Reflection:
Create an index card poster that defines the force formula and Newton’s second Law.
Include:
Definitions of force, mass, acceleration
Explanation of the formula and the Second Law
Draw at least three examples of the law in action

15. Big Idea
As an object’s mass increases, the amount of force required to move the object increases as well. The same is true if the object’s mass decreases.

16. Big Idea:
The more mass an object has, the more force you need to cause it to accelerate (move).
The less mass an object has, the less force you need to cause it to accelerate.

17. Summary:
In your notes summarize what you have learned in 3-5 sentences.

18. 5 E Evaluate: 5 Question Quiz
Elaborate: Write a 3-5 panel comic strip to show how Newton’s Second Law works.
Explain: Cornell Notes on N’sSL
Explore: Ping Pong/ Golf Ball Striking Activity
Engage: Watch NSL video: