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Newton's Laws Part 2 - Newton's 3rd Law

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This lesson provided by:

Author:	Jesse Bouldin
System:	Alexander City
School:	Alexander City Board Of Education
The event this resource created for:	ASTA

General Lesson Information

Lesson Plan ID:	34563
Title:	Newton's Laws Part 2 - Newton's 3rd Law
Overview/Annotation:	As the second installment of a series of lessons on Newton's 3 Laws of Motion, this lesson focuses on Newton's Third Law. Students will take part in an activity exploring the motion of colliding objects. Students will photograph these collisions as a demonstration and explain how Newton's 3rd Law and balanced & unbalanced forces relate to their collision. This lesson results from a collaboration of the Alabama State Department of Education and ASTA.

Associated Standards and Objectives

Content Standard(s):

Science
SC2015 (2015)
Grade: 8
Physical Science

10 ) Use Newton's third law to design a model to demonstrate and explain the resulting motion of two colliding objects (e.g., two cars bumping into each other, a hammer hitting a nail).*

NAEP Framework

NAEP Statement::
P8.16a: Forces have magnitude and direction.

NAEP Statement::
P8.16b: Forces can be added.

NAEP Statement::
P8.16c: The net force on an object is the sum of all the forces acting on the object.

NAEP Statement::
P8.16d: A nonzero net force on an object changes the object's motion; that is, the object's speed and/or direction of motion changes.

NAEP Statement::
P8.16e: A net force of zero on an object does not change the object's motion; that is, the object remains at rest or continues to move at a constant speed in a straight line.

Unpacked Content

Scientific And Engineering Practices:

Developing and Using Models

Crosscutting Concepts: Systems and System Models

Disciplinary Core Idea: Motion and Stability: Forces and Interactions

Evidence Of Student Attainment:

Students:

Design a model of two colliding objects.
Demonstrate Newton's Third Law, which states that for any pair of interacting objects, the force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first, but in the opposite direction.
Use Newton's Third Law to explain the resulting motion of two colliding objects.

Teacher Vocabulary:

Sir Isaac Newton
Newton's Third Law of
Motion
Force
Model
Mass
Speed
Velocity
Action
Reaction

Knowledge:

Students know:

Whenever two objects interact with each other, they exert forces upon each other.
These forces are called action and reaction forces; forces always come in pairs.
For every action, there is an equal and opposite reaction.
The size of the force 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.
The momentum of an object increases if either the mass or the speed of the object increases or if both increases.
The momentum of an object decreases if either the mass or the speed of the object decreases or if both decrease.

Skills:

Students are able to:

Develop a model that demonstrates Newton's third law and identify the relevant components.
Describe the relationships between components of the model.
Use observations from the model to provide causal accounts for events and make predictions for events by constructing explanations.

Understanding:

Students understand that:

Newton's Third Law states that for any pair of interacting objects, the force exerted by the first object on the second object is equal in strength to the force that the second object exerts on the first, but in the opposite direction.

AMSTI Resources:

AMSTI Module:
Experimenting with Forces and Motion

Alabama Alternate Achievement Standards

AAS Standard:
SCI.AAS.8.10- Describe the motion of two colliding objects before and after the collision.

Local/National Standards:

Primary Learning Objective(s):

Learning Target:

I will use the partner balance challenge to demonstrate and explain the action-reaction sequence of two objects colliding.

Additional Learning Objective(s):

Preparation Information

Total Duration:	31 to 60 Minutes
Materials and Resources:	A safe environment with space for students to actively move.
Technology Resources Needed:	Laptop, tablet/iPad, or smartphone to record an image and edit and label the photograph. Ability to show online videos in the classroom. Physics of Football - Newton's Third Law of Motion
Background/Preparation:	Students should have a general understanding of Newton's 3rd Law and the differences in balanced & unbalanced forces.

Procedures/Activities:

Before/Engage:

Begin by showing the following video as a refresher of how Newton's 3rd Law applies to colliding objects: Physics of Football - Newton's Third Law of Motion

During/Explore/Explain:

Students will demonstrate the reactions of colliding forces by playing the balance challenge game in groups. The game is played by standing

The game is played by standing facing your partner about two feet apart (your fingertips should reach your opponents chest). Your hands must always remain upright with palms facing out and you may only touch your opponent on their hands. The object of the game is to push your opponent off balance or to move your hands back so that your opponent will fall off balance. Allow students to play a few rounds in groups. Follow this exploration with group discussion questions such as:

The object of the game is to push your opponent off balance or to move your hands back so that your opponent will fall off balance. Allow students to play a few rounds in groups. Follow this exploration with group discussion questions such as:

Allow students to play a few rounds in groups. Follow this exploration with group discussion questions such as:

A) What are two ways to create an unbalanced force in this game?

B) How does Newton's 3rd Law or action-reaction pairs relate to what you're doing now?

After a brief discussion, have your students take a photograph of a picture of both a balanced collision and an unbalanced collision. Have them label and explain how each of these collisions demonstrate action-reaction pairs. Examples are provided in the attachment area.

After/Elaboration:

Once the activity is complete, have students write a reflection in their journal (or notebook) on the following topics:

1) When two objects collide, what forces determine how the objects will move?

2) What is one thing that you learned or surprised you about objects colliding?

3) What is one question you still have about Newton's 3rd Law or colliding objects?

Assessment

Assessment Strategies

Evaluation:

The class discussion, labeled photograph, and reflective journal are all forms of formative assessments to determine if students can explain the action-reaction sequence of two objects colliding.

Acceleration:	A) Students can photograph & explain collisions using additional objects or props. B) Just for fun - Students can compete in a class tournament to find the winner of the balance challenge game. C) For an additional activity on Newton's 3rd Law that students can participate in or simply observe, view this video: https://youtu.be/5eirTBW0rpI
Intervention:	Assign peer partners or other good helpers in groups with students who need remediation.

View the Special Education resources for instructional guidance in providing modifications and adaptations for students with significant cognitive disabilities who qualify for the Alabama Alternate Assessment.

ALEX Lesson Plan

Newton's Laws Part 2 - Newton's 3rd Law