G8 C02 W1: Week 1 Content - Kairos Academy Skip to main content

Week 1: Week 1 Content

Grade 8 Science | Rosche | Kairos Academies

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**Choose Your Path:** Select one of the following investigation pathways based on your interests: - **Path A:** Propulsion Engineering - Design rocket or fan-powered vehicles using Newton's Third Law - **Path B:** Sports Physics - Analyze force pairs in athletic movements (running, swimming, jumping) - **Path C:** Transportation Systems - Study how boats, cars, and aircraft use action-reaction principles

**Specialist Track:** As you progress, you'll develop expertise in force analysis and motion prediction. Advanced learners: try the multi-force system challenge at the bottom of this page.

**Career Connection:** Mechanical engineers, aerospace designers, and biomechanics researchers use Newton's Laws daily in careers like vehicle design, robotics, sports science, and prosthetics development. High school physics and AP mechanics build directly on these three laws.

**You're in Control:** Design your own propulsion system to answer: "How can I create motion using only action-reaction forces?" Use the engineering design process, but YOU decide the design approach, materials constraints, and testing strategy.

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Accessibility & Learning Support

  • Need text read aloud? Chrome: Right-click then "Read aloud" | Edge: Click speaker icon in address bar
  • Working from home? Look for the HOME ALTERNATIVE boxes at each station
  • Need extra support? Click the green "Need help?" buttons for hints and sentence starters
  • Stuck? Look for the red "Stuck?" boxes with step-by-step help

NGSS Standards Covered This Week

MS-PS2-1 (Introduction - mastered in Week 3)

What it means: Apply Newton's Third Law to design a solution to a problem involving the motion of two colliding objects.

In student language: I can identify action-reaction force pairs and use them to design propulsion systems.

MS-PS2-2 (Foundation - mastered in Week 2)

What it means: Plan an investigation to provide evidence that the change in an object's motion depends on the sum of the forces on the object and the mass of the object.

In student language: I can explain how force and mass affect acceleration (introduction to F=ma).

3-Dimensional Learning

Dimension What You'll Practice
SEP-6 Constructing Explanations Explain motion using Newton's Three Laws
DCI PS2.A Forces and Motion Learn how forces cause changes in motion
CCC-2 Cause and Effect Forces cause acceleration
CCC-4 Systems and System Models Force pairs act on different objects in a system

Success Criteria - How You'll Know You've Got It

Target 1: Explain Newton's First Law (Law of Inertia)

Self-check: Can I explain why a skateboard keeps rolling even after you stop pushing?

Target 2: Explain Newton's Second Law (Force causes acceleration)

Self-check: Can I describe how force and mass affect acceleration?

Target 3: Identify action-reaction force pairs (Newton's Third Law)

Self-check: Can I explain why both you AND the boat move when you jump off?


Why This Matters to YOU:

Every time you walk, run, swim, or ride in a car, Newton's Laws are at work. They explain rocket launches, athletic performance, why seatbelts save lives, and govern ALL motion in the universe.


The Phenomenon: The Boat Jump Paradox

Imagine this scenario:

  • You stand on a small boat or skateboard at rest
  • You jump forward - pushing the boat backward with your feet
  • You move forward through the air (as expected)
  • The boat moves backward (the paradox!)
  • Even stranger: If the boat is lighter than you, it moves faster backward than you move forward!

Why do both you AND the boat move in opposite directions? Why does the lighter object move faster?

Focus Question: Why do you move backward when you jump off a boat?

Learning Targets

By the end of this week, you will be able to:

Sir Isaac Newton: Laws of Motion

Sir Isaac Newton (1643–1727) was an English mathematician, physicist, and astronomer who fundamentally transformed our understanding of the physical universe. In 1687, Newton published Philosophiæ Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), one of the most influential scientific works ever written. In this book, he presented his Three Laws of Motion—the exact laws you're studying this week.

What makes Newton's achievement extraordinary is that these three simple laws explain EVERYTHING from falling apples to planetary orbits to rocket propulsion. Before Newton, people thought celestial bodies (planets, stars) followed different rules than earthly objects. Newton unified physics by showing the same laws govern all motion everywhere in the universe. The force that makes an apple fall is the same force that keeps the Moon orbiting Earth—gravity, described by these very laws.

Newton's Third Law—"For every action, there is an equal and opposite reaction"—is particularly powerful because it's counterintuitive. When you push a wall, the wall pushes back with equal force. When you walk forward, you push Earth backward. These insights revolutionized engineering, enabling the design of vehicles, rockets, bridges, and machines. Every spacecraft that has launched into orbit, every airplane that has flown, every car that has driven—all rely on Newton's Laws.

As you learn about Newton's Laws this week, you're following in the intellectual tradition of one of history's greatest scientists. These laws have remained unchanged for over 300 years—a testament to their power and accuracy. (Only at extreme speeds approaching the speed of light do Einstein's relativity corrections become necessary—but for everyday motion, Newton's Laws are perfect.)

Why This Matters in St. Louis

St. Louis is a major transportation hub—freight rail, Lambert Airport, Mississippi River barges—all operate using Newton's Laws. MetroLink uses F=ma for braking calculations. Boeing's aerospace division designs aircraft using Newton's Third Law (jet engines push gases backward, creating forward thrust). Autonomous vehicle software being tested in Missouri uses these exact laws to calculate stopping distances and predict collisions—the principles you're learning this week!

Vocabulary

Key Vocabulary (7 terms) — Practice Tool

Cognate Strategy: Many science words look similar in English and Spanish — use your Spanish to learn science!

Term Spanish Definition
force A push or pull on an object
motion Movement; change in position over time
inertia inercia Resistance to changes in motion
acceleration aceleración Change in speed or direction
mass masa Amount of matter in an object
action acción One force in a force pair (Newton's Third Law)
reaction reacción The equal-opposite partner force

Worked Example

Common Mistake: "Objects need force to keep moving"

WRONG: "Objects stop moving when the force runs out."

RIGHT: "Objects keep moving at constant speed unless a force acts on them (Newton's First Law). Friction is the force that slows things down, not "running out of force.""

Common Mistake

Target 4: Apply Newton's Third Law to design a propulsion system

Self-check: Can I design a device that moves using action-reaction forces?

Step-by-Step Problem Solving

Problem Scenario

Review the problem scenario and work through each step below.

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Need extra support? Click here for hints and sentence starters

Key Concept Reminder:

  • Inertia = resistance to motion changes (NOT a force!)
  • Force = push or pull that causes acceleration
  • Acceleration = ANY change in motion (speed up, slow down, turn)

Sentence Starters:

  • "According to Newton's First Law, objects..."
  • "Newton's Second Law says that force causes..."
  • "The difference between N1L and N2L is..."

Word Bank:

inertia, resist, force, acceleration, mass, at rest, in motion, constant velocity, unbalanced force

Stuck? Click here for step-by-step help

Try these steps in order:

  1. Read the law definition carefully (in the blue box above)
  2. Look at the examples in the table - which law applies?
  3. Ask yourself: "Is the object resisting change (N1L) or is a force causing acceleration (N2L)?"
  4. Use the sentence starters to organize your thinking
  5. Still stuck? Email Mr. Rosche with your specific question

COMPLETE THE STATION 1 FORM BELOW

Apply Newton's First and Second Laws to scenarios.

[EMBED G8.C2.W1 Station 1 Form Here]

Form ID: ________________


Station 2 - Action-Reaction Pairs (Newton's 3rd Law)

20 Points | ~15 Minutes

Your Mission: Identify Force Pairs in Real Scenarios

Newton's Third Law (Action-Reaction):

"For every action force, there is an equal and opposite reaction force."

Translation: Forces always come in pairs. When Object A pushes Object B, Object B pushes Object A back with EQUAL force in the OPPOSITE direction. The forces act on DIFFERENT objects.

CRITICAL: The force pairs are ALWAYS equal in magnitude, but they act on DIFFERENT objects, so they don't cancel out!

Common Misconception Alert!

Students often think "the boat doesn't move because it's heavier." WRONG! Newton's Third Law says the forces are ALWAYS equal. The boat DOES move—just with less acceleration because it has more mass (that's N2L: a = F/m).

Force Pair Examples:

Scenario Action Force Reaction Force Result
Boat Jump You push boat backward Boat pushes you forward Both move opposite directions
Rocket Launch Rocket pushes gas downward Gas pushes rocket upward Rocket accelerates up
Walking Foot pushes ground backward Ground pushes foot forward You move forward
Swimming Hands push water backward Water pushes hands forward You move forward
Need extra support? Click here for hints

How to Find Force Pairs:

  1. Identify the TWO objects interacting
  2. Action: Object A pushes/pulls Object B
  3. Reaction: Object B pushes/pulls Object A (equal, opposite)
  4. Remember: Forces on DIFFERENT objects (don't cancel)

Sentence Starters:

  • "The action force is... pushing/pulling..."
  • "The reaction force is... pushing/pulling back..."
  • "Both forces are equal because... (N3L)"

COMPLETE THE STATION 2 FORM BELOW

Identify action-reaction force pairs in different scenarios.

[EMBED G8.C2.W1 Station 2 Form Here]

Form ID: ________________


Station 3 - Design a Propulsion System

25 Points | ~20 Minutes (Highest Value!)

Engineering Challenge: Design Using Newton's Third Law

YOUR CHOICE: Select Your Propulsion Design Path

You have THREE design options for creating a propulsion system. YOU choose the one that interests you most! All three can earn full points.

Path A: Balloon Rocket (Aerospace Engineering)

Design a balloon-powered rocket that travels along a string. As the balloon releases air backward (action), the balloon moves forward (reaction). Optimize for distance traveled. If you're interested in rockets, space exploration, or aerospace, choose this path.

Path B: Fan Cart (Mechanical Engineering)

Design a wheeled cart powered by a battery-operated fan. The fan pushes air backward, and the air pushes the cart forward. Optimize for speed and control. If you're interested in vehicles, robotics, or mechanical systems, choose this path.

Path C: Water Jet Propulsion (Marine Engineering)

Design a boat propelled by squirting water backward through a nozzle (like a squid!). Water pushed backward creates forward thrust. Optimize for thrust and stability. If you're interested in boats, submarines, or fluid dynamics, choose this path.

Why This Matters: Real engineers choose design approaches based on constraints and goals. Your choice reflects authentic engineering decision-making!

Your Mission:

Design a device that moves using action-reaction forces (Newton's Third Law).

Design Requirements:

  • Action force: What pushes what?
  • Reaction force: What pushes back?
  • Prediction: Which direction will your device move?
  • Optimization goal: Distance, speed, or control?

Your Design Must Include:

Component What to Include
Design Sketch Labeled diagram showing all parts
Force Pair Identification Action force + reaction force (with arrows)
Direction Prediction Which way will it move and why?
N3L Explanation How does Newton's Third Law make it work?
Creative Element What makes your design unique or optimized?
Need extra support? Click here for design hints

Design Tips:

  • Start with the action force: What will you push backward?
  • Identify the reaction: What pushes your device forward?
  • Draw arrows showing force directions (action ← device → reaction)
  • Explain using N3L: "When X pushes Y, Y pushes X with equal force"

Sentence Starters:

  • "My device works by pushing [what] in [direction]..."
  • "According to Newton's Third Law, when I push [object], it pushes back with..."
  • "The reaction force causes my device to move [direction] because..."

COMPLETE THE STATION 3 FORM BELOW

Design your propulsion system and explain using Newton's Third Law!

[EMBED G8.C2.W1 Station 3 Form Here]

Form ID: ________________


Exit Ticket - Newton's Laws Mastery Check

23 Points | ~15 Minutes

Show What You Learned

Question Types:

  • 4 NEW - Newton's First, Second, and Third Laws
  • 0 SPIRAL - This is Week 1 of Cycle 2! No prior C2 content to review yet.
  • 1 INTEGRATION - Connect Newton's Laws to Cycle 1 energy concepts
  • 1 SEP-6 - Constructing explanations for engineering designs

Remember:

This is your first Exit Ticket of Cycle 2! Next week, you'll have spiral questions reviewing Newton's Laws while learning F=ma (the quantitative version of Newton's Second Law).

COMPLETE THE EXIT TICKET BELOW

This is your final assessment for Week 1. Take your time!

[EMBED G8.C2.W1 Exit Ticket Form Here]

Form ID: ________________



Enrichment & Extension
Optional deep dives for early finishers.

Optional content if you finish early or want to go deeper.

Scientist Spotlight

Research a scientist who contributed to this week's topic area and describe their key findings.

Environmental Justice Connection

Explore how this week's science concepts connect to environmental justice issues in our community.

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