Middle School NGSS Resource Hub
Three-dimensional breakdowns, phenomenon ideas, misconceptions, and engagement activities for every NGSS middle school standard.
🚀 Jump to Your Discipline
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→Physical ScienceMS-PS1 to MS-PS4 • 19 standards
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→Life ScienceMS-LS1 to MS-LS4 • 21 standards
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→Earth & SpaceMS-ESS1 to MS-ESS3 • 15 standards
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→EngineeringMS-ETS1 • 4 standards
Middle School NGSS Standards
Pick any standard. Each page is your full lesson-planning workspace for that standard.
Newton's Third Law in Collisions: Designing a Bumper That Actually Protects Something
"Apply Newton's Third Law to design a solution to a problem involving the motion of two colliding objects."
"Examples of practical problems could include the impact of collisions between two cars, between a car and stationary objects, and between a meteor and a space vehicle."
"Assessment is limited to vertical or horizontal interactions in one dimension."
The three dimensions packed into this standard
Every standard bundles a DCI (the content), a SEP (the science practice), and a CCC (the crosscutting lens). They run in the same task, not in sequence.
"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 (Newton's third law)."
When two objects interact, they push on each other with equal force in opposite directions. Always. The car pushes the wall, the wall pushes back just as hard. The forces in the pair are simultaneous, equal in size, opposite in direction, and they act on different objects. That last part is the one students miss. The two forces aren't on the same thing.
"Apply scientific ideas or principles to design an object, tool, process or system."
Students aren't just learning a law. They're using it to design a solution. The standard pairs the physics with engineering: pick a collision problem (a fragile cargo, a passenger, a phone), then design a device that reduces the force during impact. The science idea drives the design choice. If the design doesn't connect back to force pairs, it's craft time.
"Models can be used to represent systems and their interactions, such as inputs, processes and outputs, and energy and matter flows within systems."
A collision is a system with two objects, the force pair between them, and whatever you build to sit between them. Students model that system with a sketch or diagram showing the force arrows, the objects, and where the design feature lives. The model is the thinking tool. It shows where energy and force flow during the moment of impact.
📍 Where This Standard Fits in the K-12 Progression
Use this to plan the year. Knowing what students should already know and what they're heading toward keeps the lesson focused.
Each push or pull has both a strength and a direction. When two objects push or pull on each other, both objects feel a force, even if one of them ends up moving more than the other.
Newton's Third Law in Collisions: Designing a Bumper That Actually Protects Something
Use Newton's second law (F = ma) with numbers to predict and explain motion. Analyze collisions and interactions quantitatively using momentum and the idea that total momentum is conserved when no outside force acts on the system.
🌎 Phenomena for MS-PS2-1
Anchor the lesson in one puzzling phenomenon kids keep coming back to. Use the two investigative phenomena to sharpen specific facets.
The Egg That Survives a Wall
A raw egg taped to a small toy car. The car rolls down a ramp at the same speed in two trials. In trial one, the car hits a bare wall and the egg cracks. In trial two, the car hits the same wall, but with a pile of crumpled paper towels stacked in front. The egg survives. Same ramp. Same car. Same wall. Different outcome. Students will keep circling back to this all week.
"What did the crumpled paper towels actually change about the crash?"
- "Why didn't the towels just slow the car down before it hit?"
- "Did the wall push the car less hard the second time?"
- "Could we use the same idea to protect a phone, a passenger, a window?"
The Skater and the Wall
A short video clip of an ice skater pushing off a smooth wall with both hands. The wall doesn't move. The skater glides backward. Almost nothing was touching her except the wall, so where did her motion come from? Use this to sharpen the force-pair lens the anchor is pushing on: every push is two pushes, on two different things.
"If the wall didn't push her, what made her move?"
- "Does the wall push her back even though the wall stays still?"
- "Would she move the same if she pushed off a smaller wall, like a free-floating board?"
- "What if she pushed off another skater instead of a wall? What would happen to both of them?"
Balloon Car Across the Floor
A small car with a balloon taped to the top, the balloon's neck pointing out the back. Inflate the balloon, let it go, and the car shoots forward. The air rushes backward out of the balloon. The car goes the other way. Same kind of push-pair as the skater on the wall, only here both objects are free to move. Use this to extend the lens further: when nothing is holding either object in place, both move in opposite directions from a single force pair.
"If the air is what's moving, how is the car moving too?"
- "Is the air pushing the car, or is the car pushing the air?"
- "Would a heavier car go slower? Would a lighter car go faster?"
- "What if the balloon was bigger? What if the opening was wider?"
⚠️ Misconceptions Your Students Will Walk In With
These come up almost every year. Knowing them in advance lets you head them off in the first lesson.
"The bigger object pushes harder than the smaller one."
No. The forces in a Newton's-third-law pair are always equal in size. A semi-truck and a bicycle collide, both feel the exact same force at the moment of impact. The bicycle moves more because it has less mass (acceleration = force divided by mass). The forces are equal. The results aren't.
"Action and reaction forces cancel each other out."
They look like they should, but they don't. The two forces act on different objects. You can only cancel forces that act on the same object. The wall pushes the car backward and the car pushes the wall forward, but the wall doesn't move (much) because the ground pushes it back too. Same-object forces cancel. Pair forces don't.
"The reaction force happens after the action force."
They happen at the exact same moment. There's no first and second. The instant your foot pushes the floor, the floor pushes your foot. You can't have one without the other. The word "reaction" is a little misleading. They're simultaneous.
"A softer bumper changes how much force the wall pushes with."
The total push between the two objects is set by the collision. What a softer bumper changes is how long that push takes to happen. Spread the same push over more time and the force felt at any one instant gets smaller. The bumper doesn't shrink the total force. It stretches the force over a longer impact.
🙋 Common Student Questions and How to Respond
These come up almost every time this standard gets taught. Plan a response and you'll keep the lesson focused.
Both feel exactly the same force at impact. The reason they look different afterward is mass. The car has less of it, so the same force changes its motion more. Same force on the truck barely budges it because it's huge. The damage isn't a sign of bigger force. It's a sign of smaller mass moved more.
They stretch the crash out. Without them, your body stops in the time it takes to hit the dashboard, which is super short. The shorter the stopping time, the bigger the force on you. A seatbelt slows your body over a longer distance and time, and an airbag adds even more. Same change in motion. Spread out longer. Smaller force at any moment.
The wall does feel the push from you, equal in size, opposite in direction. But the wall is connected to the floor and the building, which are connected to the Earth. You'd have to push hard enough to move all of that at once. Your push is real. The wall just has too many things holding it in place to respond.
The second law tells you what one force does to one object: bigger force or smaller mass means more change in motion. The third law tells you that forces always come in pairs between two objects. Second law is one object, one force. Third law is two objects, two forces, equal and opposite. Different jobs, both true at the same time.
📚 Vocabulary Students Need for MS-PS2-1
Twelve terms students need to access this standard. Definitions in plain-English, classroom-ready language.
A push or a pull. Has size and direction. Measured in newtons.
When one object pushes on another, the second object pushes back with equal size in the opposite direction. Always.
The two equal-and-opposite forces that show up whenever two objects interact. The two forces act on different objects, not the same one.
The push or pull one object applies to another. Naming it "action" is a convention. There's no first and second in a pair.
The push back from the second object on the first, equal in size, opposite in direction. Happens at the same instant as the action force, not after.
Any moment when two objects exert force on each other. Collisions, contact, magnetism, gravity. All interactions produce force pairs.
A moment when two objects make contact and exchange force. Cars, carts, a ball and a wall, two skaters bumping. Anytime two things hit each other.
How long the two objects stay in contact during a collision. Stretch this out, and the force felt at any one moment gets smaller.
A built-in part of a vehicle (or a device) that deforms during a collision to extend contact time. The crushing is the feature, not a failure.
The set of objects you're paying attention to and the interactions between them. In this standard, the colliding objects plus any protective device.
What the design has to do to count as a success. For a bumper: protect the clay below a target deformation, at a target ramp height, in a single trial.
The limits the design has to work inside. Materials available, size of the bumper, time to build, budget.
💡 Free Engagement Ideas for MS-PS2-1
Force-Pair Card Sort
Students sort 12 collision scenario cards (rocket and exhaust, hand and table, foot and floor, swimmer and water, car and wall, etc.) and identify the two objects involved and the direction of each force in the pair. They use arrow stickers to mark each object with the force it feels. The goal is fluency in spotting force pairs in everyday situations before any design work starts.
Bumper-Build Sprint, v1
Teams build a first bumper for a toy car or PASCO cart, using a small piece of modeling clay as the "passenger." Same ramp height, same cart, same clay mass every trial. Teams measure the clay's width before and after the crash and record the deformation. The number is the proxy for how much force the passenger felt.
One-Variable Bumper Redesign
Between v1 and v2, teams take 15 minutes to look at their v1 clay deformation, pick ONE feature of the bumper to change (material, thickness, layered vs. solid, with a crumple shape vs. flat), and write one sentence predicting what the v2 deformation will be and why. The discipline of changing one variable is the whole point.
Force-Pair Diagram Gallery Walk
After v2, each team posts their best bumper next to a force-pair diagram of the moment of impact. Arrows on different objects. Labels on the system. Teams walk the room and leave a sticky note on each board with one strength and one question. Students see how other teams thought about the same physics differently.
📝 Assessment Ideas for MS-PS2-1
Three short tasks that hit all three dimensions. Doable in one class period each.
Students submit a structured report covering their v1 bumper, the v1 clay deformation result, the variable they changed and why, the v2 bumper, the v2 result, and a side-by-side comparison. A force-pair diagram of the collision (arrows on the cart and on the wall) is required. The writeup has to use criteria and constraints language and connect the design choice to force-pair reasoning.
Students get four collision scenarios in writing (a bird flying into a window, a foot kicking a soccer ball, a hammer hitting a nail, two skaters colliding). For each one, they draw the two objects and label the force pair with two arrows of equal length, on the two different objects, pointing in opposite directions. They write one sentence per scenario naming which object is which and what each arrow represents.
Students get a written description and sketch of a bumper that failed to protect the clay in v1 (clay deformed 8 mm, the target was under 3 mm). They identify two specific features the designer should change for v2 and explain how each change would reduce the force the clay feels, using force-pair language and contact-time reasoning.
🎯 What Proficient Student Work Looks Like
Same prompt, three student responses at different proficiency levels. Use as anchor papers when scoring.
"Submit your v1 + v2 bumper design report. Include your v1 design and result, the variable you changed, your v2 design and result, a force-pair diagram of the collision, and a comparison of the two runs."
- A specific claim backed by data, observation, or model
- Use of standard-specific vocabulary in context
- Connection between the visible and the underlying explanation
- A question they're still wondering about (curiosity stays alive)
We made a bumper out of bubble wrap. The clay smooshed less. For v2 we added more bubble wrap and it smooshed even less. v2 was better than v1.
Names a design and a change, but no numbers. No force-pair diagram. No reason for the change tied to physics. Doesn't use criteria, constraints, or contact-time language. Stops at "v2 was better."
Our v1 bumper used one layer of bubble wrap taped to the front of the cart. The clay was 15 mm wide before the crash and 10 mm wide after, so it deformed 5 mm. The criteria was less than 3 mm of deformation, so v1 missed. For v2 we added a second layer of bubble wrap because the v1 layer wasn't soft enough to stretch out the contact time. v2 deformed 2 mm. [Includes a force-pair diagram showing two equal arrows pointing in opposite directions, one on the cart and one on the wall.] The bumper made the crash last longer, so the force the clay felt at any moment was smaller, even though the total push between the cart and the wall stayed the same.
Specific numbers. Named variable change. Reason tied to v1 data. Force-pair diagram with arrows on different objects. Uses contact-time language without invoking momentum or impulse. This is exactly what the standard is targeting.
Our v1 bumper was a flat 1 cm layer of foam glued to the front of the cart. v1 clay deformation was 7 mm. The criteria was under 3 mm, so v1 missed by a lot. We thought about adding more foam, but more material wasn't really the variable. The issue was that the flat foam compressed all at once, so the crash was still short. For v2 we kept the same total foam thickness (1 cm) but cut it into a honeycomb / crumple pattern so different parts of the bumper would compress at slightly different moments. v2 deformed 2 mm. [Includes a force-pair diagram with labeled arrows on the cart and on the wall, plus a side-view sketch of the v1 flat foam vs. the v2 crumple foam.] The total push the wall gave back to the cart was the same in both trials (Newton's third law). What changed was how long the cart was pushing on the wall. The crumple shape stretched the contact time, so the force the clay felt at any one moment was smaller. The chemistry of the foam didn't change. The engineering of the shape did.
Distinguishes a material change from a structural change. Reasons about why "more foam" isn't automatically the right answer. Force-pair diagram is accurate (arrows on different objects, equal length). Connects the structural change to contact time without invoking momentum or impulse math. This is exactly the engineering-meets-physics reasoning the standard targets.