Students solve multi-step force and motion problems using F = ma and a = Δv ÷ t with correct units, use a graph to support a quantitative argument, and check answers for reasonableness (AC9S10U05, node 7, a practise node).
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 3 min · Explain 12 min · Evaluate 3 min · Typical adds 1 min, Wider about 1 min
A practice lesson with no simulation, following Free body diagrams. Set the width with ?width=minimum, typical (default) or wider. The Year 10 progression marks this node as a place for structured practice, so students need pencil and calculator more than a screen: ask them to show each line in their books before entering an answer.
Answers with a sign are entered as numbers (−2.5). Round figures are chosen for clean numbers; real braking and engine forces vary with speed.
Choosing the step, not just the formula. When a student reaches for a number, ask what quantity it is and which step it belongs to.
| What you will see | A question to ask | The fix |
|---|---|---|
| A student uses the engine force alone. | What other force acts, and which way? | Resistance, backwards. F in F = ma is the net force. |
| A student gets a huge or tiny answer. | Does a mass in grams or a time in minutes appear anywhere? | Convert to kg and s first. |
Stretch: A 1000 kg car has a braking force of 5000 N while travelling at 30 m/s. How long does it take to stop, and how far does it go? (6 s; 90 m, the area under the speed–time graph.)
Support: Give a five-line template (Known, Net force, Acceleration, Speed or time, Reasonable?) with the first line filled in.
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 "Solving force and motion problems". The idea: Quantitative problem solving — integrating all three laws: I can solve multi-step force and motion problems that require selecting and applying Newton's laws, using mathematical representations including graphs and algebraic formulas. What understanding looks like: - Solves a multi-step problem applying at least two of Newton's laws with correct units throughout - Uses mathematical representations (graphs or algebraic formulas) to support a quantitative argument - Checks the reasonableness of a calculated answer in physical terms Mistakes students often make here: - A student uses the engine force alone. - A student gets a huge or tiny answer. 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 (Multi-force analysis and free body diagrams), 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 "Solving force and motion problems".
A 50 kg skateboarder is pushed with a net force of 100 N from rest. How fast is she moving after 4 s?
a = 100 ÷ 50 = 2 m/s². After 4 s: 2 × 4 = 8 m/s.
Next: Newton's laws in the real world.
In class: collect braking data with a toy car and a ramp; use a speed–time graph from a data logger; work through a vehicle's stopping distance table.