Science · Year 10

Active learning ideas

Newton's Third Law and Interactions

Active learning helps Year 10 students grasp Newton’s Third Law because it makes abstract force pairs visible and interactive. When students physically push, collide, or propel objects, they experience firsthand how paired forces act on different bodies, building intuition beyond textbook descriptions.

• ACARA Content Descriptions
• AC9S10U07

• 20–50 min
• Pairs → Whole Class
• 4 activities

Activity 01

• Experiential Learning
• 20 min · Pairs

Demonstration: Partner Push-Off

Pairs stand back-to-back on low-friction rollers or ice skates and push against each other. They observe both move apart equally despite size differences. Discuss how forces are equal but act on separate bodies.

How does Newton's First Law explain why objects in space continue moving in a straight line at constant speed without any propulsion?

Facilitation Tip

During Partner Push-Off, have students measure and record their push forces using bathroom scales held between their hands to quantify equal and opposite forces.

What to look for

Present students with an image of a person jumping off a diving board. Ask them to: 1. Identify the action force. 2. Identify the reaction force. 3. Explain why the person moves upward while the board moves downward.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

Activity 02

• Collaborative Problem-Solving
• 45 min · Small Groups

Collaborative Problem-Solving: Balloon Rocket Cars

Small groups build cars from straws, balloons, and CDs, then launch on a string track. Measure distances and repeat with varying balloon sizes. Record action (air expulsion) and reaction (car motion).

What everyday examples best demonstrate Newton's Third Law , and why do the paired forces not simply cancel each other out?

Facilitation Tip

For Balloon Rocket Cars, ensure students measure the distance traveled across three trials and calculate average speed to reinforce quantitative analysis of motion.

What to look for

Pose the question: 'A truck collides with a small car. According to Newton's Third Law, the force the truck exerts on the car is equal and opposite to the force the car exerts on the truck. Why does the car experience much greater damage?' Facilitate a discussion focusing on mass, acceleration, and the definition of a system.

• Apply
• Analyze
• Evaluate
• Create
• Relationship Skills
• Decision-Making
• Self-Management

Activity 03

• Inquiry Circle
• 50 min · Whole Class

Inquiry Circle: Cart Collisions

Whole class sets up dynamics carts on tracks for elastic and inelastic collisions. Predict and measure speeds before/after using timers. Analyze force pairs during impacts.

How do Newton's three laws work together to fully describe the motion of an object under the influence of multiple forces?

Facilitation Tip

In Cart Collisions, set up motion sensors or ticker timers to record velocity changes before and after collisions, helping students link force pairs to momentum changes.

What to look for

Ask students to draw a diagram illustrating a bird in flight. They should label at least one action-reaction force pair involved in the bird's ability to fly and briefly explain how these forces contribute to its motion.

• Analyze
• Evaluate
• Create
• Self-Management
• Self-Awareness

Activity 04

• Experiential Learning
• 30 min · Pairs

Extension: Fan Boat Races

Pairs construct boats from foam, ping pong balls, and small fans. Test in water trays, timing races. Identify action-reaction in propeller thrust versus boat motion.

How does Newton's First Law explain why objects in space continue moving in a straight line at constant speed without any propulsion?

Facilitation Tip

During Fan Boat Races, challenge teams to adjust fan angle and predict how thrust direction affects boat speed and stability before each trial.

What to look for

Present students with an image of a person jumping off a diving board. Ask them to: 1. Identify the action force. 2. Identify the reaction force. 3. Explain why the person moves upward while the board moves downward.

• Apply
• Analyze
• Evaluate
• Self-Awareness
• Self-Management
• Social Awareness

A few notes on teaching this unit

Experienced teachers approach Newton’s Third Law by starting with students’ own bodies and simple interactions before moving to complex systems. Avoid spending too much time on verbal explanations alone; prioritize hands-on exploration so students confront misconceptions through evidence. Research shows that letting students feel paired forces directly—rather than just hearing about them—reduces confusion about cancellation and timing. Emphasize systems thinking: help students see that forces act on different objects, not within the same one.

Successful learning shows when students can identify action-reaction force pairs, explain why paired forces don’t cancel, and predict motion changes in different systems. They should connect these pairs to real-world examples and apply the law to explain why objects move or stay at rest under multiple forces.

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Watch Out for These Misconceptions

• During Partner Push-Off, watch for students who say the forces cancel each other out, preventing motion.

  During Partner Push-Off, have students stand on slippery surfaces (e.g., tile floors on socks) and push each other, then discuss why both move apart even though the push forces are equal. Ask them to record the distance each partner moves and connect this to the idea that paired forces act on different objects, not the same one.

• During Cart Collisions, watch for students who believe heavier carts push with greater force.

  During Cart Collisions, provide carts of different masses and force sensors. Have students predict which cart will recoil faster and why, then analyze sensor data showing equal force magnitudes. Ask them to explain how acceleration depends on mass using F=ma, linking Newton’s Second and Third Laws.

• During Balloon Rocket Cars, watch for students who think the reaction force only happens after the balloon deflates.

  During Balloon Rocket Cars, have students hold the car stationary and release the balloon briefly to observe immediate paired forces. Use slow-motion video to show the balloon’s thrust and the car’s movement occur simultaneously. Ask students to describe the timing of forces in their lab reports, reinforcing the idea of simultaneous paired forces.

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Methods used in this brief

• Experiential Learning
• Collaborative Problem-Solving
• Inquiry Circle