• Quick retrieval from earlier learning (Balanced and unbalanced forces; Air resistance and water resistance). Students answer on mini whiteboards.
• Show answers together and note who needs support in the main task.

1. Cyclists crouch low over their handlebars in races. Why? (to see the road better / to increase friction with the road / to reduce air resistance / to make the bike heavier) → to reduce air resistancePrompt: Air pushes against the front of a moving body.
2. Why does a parachute slow a skydiver down? (It is full of helium / It turns off gravity / Its large surface creates a lot of air resistance / It makes the skydiver lighter) → Its large surface creates a lot of air resistancePrompt: The parachute pushes against lots of air.
3. Why are fish and boats streamlined (smooth and pointed)? (to increase water resistance / to reduce water resistance / to look nice / to float higher) → to reduce water resistancePrompt: A streamlined shape lets water flow past easily.

• Drop a sheet of paper and a scrunched-up sheet together and ask why one falls faster.
• Share the objective: Newton's laws of motion. Read the success criteria together.

• Work through the example out loud, saying why you do each step, not just what you do.
• Example: A passenger lurches forward when a bus brakes suddenly. Which law explains this?
• Step 1: An object keeps moving at the same velocity unless a resultant force acts (inertia).
• Step 2: So the answer is: Newton's first law (inertia)
• Answer: Newton's first law (inertia)
• Pause after each step and ask a student to say what comes next.

• Do these together. Students try each step on whiteboards before you reveal it.
• Use the hints as prompts rather than giving the answer.

1. A rocket pushes exhaust gas downwards. Why does the rocket go up? (The air underneath lifts it like a balloon / The rocket becomes lighter than air / Gravity switches off / The gas pushes the rocket upwards with an equal and opposite force) → The gas pushes the rocket upwards with an equal and opposite forcePrompt: Rockets also work in space, where there is no air.
2. Newton's laws: which statement is true? (Heavier objects need less force to accelerate. / A moving object needs a constant force to keep moving at steady speed in space. / A bigger resultant force gives a bigger acceleration for the same mass. / The two forces in a Newton's third law pair act on the same object.) → A bigger resultant force gives a bigger acceleration for the same mass.Prompt: Think about inertia, F = ma and action–reaction pairs.

• Students work on the student sheet. Circulate and check the first two answers of every student early.
• Students who finish: write a question of their own for a partner, with the answer.

The 6 questions are on the student sheet below, with answers in the key.

• Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.

1. Newton's laws: which statement is true? (The two forces in a Newton's third law pair act on the same object. / A moving object needs a constant force to keep moving at steady speed in space. / Heavier objects need less force to accelerate. / An object at rest stays at rest unless a resultant force acts on it.) → An object at rest stays at rest unless a resultant force acts on it.Prompt: Think about inertia, F = ma and action–reaction pairs.
2. Newton's laws: which statement is NOT true? (A moving object needs a constant force to keep moving at steady speed in space. / Seat belts help stop passengers continuing forward in a crash. / An object at rest stays at rest unless a resultant force acts on it. / For every force there is an equal and opposite force on the other object.) → A moving object needs a constant force to keep moving at steady speed in space.Prompt: Which two objects does each force in a pair act on?

Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-8.