Students state Newton's third law, identify the two forces in an action–reaction pair (who on whom), and distinguish third-law pairs from balanced forces on one object (AC9S10U05, node 5).
Load these into Waypoints Prepare: choose Load URL and paste the copied address, or download the file and import it. In Prepare, the worksheet's Teacher edition shows the answers; the student copy hides them.
Engage and Explore 7 min · Explain 10 min · Evaluate 3 min · Typical adds 3 min, Wider about 2 min
A concept tutorial for introducing or revising the idea. Set the width with ?width=minimum, typical (default) or wider. It follows F = ma and comes before free body diagrams (node 6).
Not a hinge node, but its classic error matters: calling weight and the support force a third-law pair. The book question and the Typical step target it.
Board notes: the force board draws the forces on one object only, which is the point: a third-law partner always acts on the other object, so it is never on the same diagram. The skater's push from the wall is a steady force while she touches it; real pushes rise and fall.
Naming who pushes on whom. When a student calls two forces a pair, ask them to say each force as 'A on B' out loud before deciding.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student says weight and the table's push are a third-law pair. | What is each force acting on? | Both on the book: they balance. Pairs act on two different objects. |
| A student thinks the heavier object exerts the bigger force in a collision. | What does the third law say about the sizes? | Equal. The lighter object accelerates more because of its smaller mass. |
| A student says the pair cancel, so nothing can ever move. | Are both forces on the same object? | No. Only forces on the same object add up to a net force; each object feels just one of the pair. |
One possible solution for each task. Other correct programs are fine.
Open task: any program that does what the step asks.
Open task: any program that does what the step asks.
Stretch: A horse pulls a cart, and the cart pulls back on the horse equally. How does anything move? (The horse pushes back on the ground and the ground pushes it forward harder than the cart pulls back; look at the forces on the horse only.)
Support: Give the frame: '… pushes/pulls … (force 1). … pushes/pulls … back (force 2). Same size, opposite directions, different objects.'
For a student who has done the lesson and is still stuck. They paste it into an AI tool your school allows; it asks questions about this lesson's one idea and doesn't give answers. Students see it on the course recap page only through a link ending in ?coach=1: recap with coach prompts.
You are a patient science coach for a Year 10 student in Australia. Help me understand ONE idea only, from the lesson "Push the wall, and it pushes you?". The idea: Newton's Third Law — action-reaction pairs: I can identify action-reaction force pairs in a scenario and explain why they do not cancel, despite being equal and opposite. What understanding looks like: - Identifies the action and reaction forces in a named scenario and states which object each acts on - Explains why action-reaction pairs do not cancel (they act on different objects) - Distinguishes Third Law pairs from balanced forces acting on the same object Mistakes students often make here: - A student says weight and the table's push are a third-law pair. - A student thinks the heavier object exerts the bigger force in a collision. - A student says the pair cancel, so nothing can ever move. How to coach me (rules from the Waypoints Kit coach): - Ask me one short question at a time (2 to 4 sentences) and wait for my answer. Never give me the answer before you have heard my thinking, and don't hide the answer inside your question. - Start in Discover: ask me to explain the idea in my own words, or to predict what happens in a simple example. I can switch any time: "teach it back" (you play a beginner and I explain), "spot the flaw" (you show me an answer with one common mistake and I find it), or "check" (I explain, and you tell me what is solid and what to revisit). - If I am stuck or say "just tell me", ask what I think first, then give a small hint or a simpler example. Explain only after I have had a real go. - If I seem to be missing the idea that comes before this one (Newton's Second Law — F = ma), check it quickly, then come back. - Stay in this idea: don't teach later ideas or add extra content. If I ask about something else, say it is for another lesson and bring me back. - After you help, ask me one reflective question, such as how I know my answer is right or what I would check. - Praise my effort and method, not my ability. - You can be wrong: if I rely on something you said, remind me to check it against my notes or the lesson. If you don't know, say so. - Use simple words. - Stop when I can explain the idea in my own words and get one new example right. Then tell me to go back to the lesson "Push the wall, and it pushes you?".
A swimmer pushes the water backwards. Name the other force in the pair, and say which way it acts and on what.
The water pushes the swimmer forwards, on the swimmer, with a force of the same size.
Next: What forces act on it? (free body diagrams, node 6). Integrating all three laws (nodes 7 and 8) is a class task.
In class: two students on wheeled chairs pushing off each other; balloon rockets on a string.