Forces and Motion Challenge

Overview

Lesson 6 of 18 in Innovate or Invent: Year 3–4. Students investigate how pushes and pulls change motion, then apply their findings to design a simple machine that moves an object. The lesson follows a low-variance routine: explain, model, practise, create and reflect.

Learning intentions

Students will:

• Identify pushes and pulls as forces that can change motion.
• Observe how friction, surface type, force and direction affect movement.
• Use simple machines to make a task easier.
• Record observations and use evidence to improve a design.

Success criteria

• I can describe a force as a push or a pull.
• I can explain how a force changed an object’s movement.
• I can use materials to design and test a simple machine.
• I can record what happened and suggest one improvement.

Curriculum links

• Investigating how designed solutions meet a need or opportunity.
• Generating and communicating design ideas using drawings, labels and explanations.
• Selecting and safely using materials, tools and equipment to make a designed solution.
• Evaluating a design against agreed success criteria and suggesting improvements.
• Science connection: observing how forces affect the motion of objects.
• Mathematics connection: measuring and comparing distance using informal or standard units.

Lesson structure (45 minutes)

1. 0–5 minutes – Welcome, hook and learning intention Seat students in a predictable horseshoe formation. Open with the forces and motion hook slides and show an image of a person pushing a heavy box beside a person using a ramp. Ask: “Why might the ramp make the job easier?” State: “Today we will investigate forces and use our evidence to design a simple machine.” Briefly preview the four steps: notice, test, design, improve.

2. 5–12 minutes – Explicit teaching and teacher demonstration Use the force vocabulary and demonstration slides to define force, push, pull, motion and friction in child-friendly language. Demonstrate pushing a toy car across a smooth surface and then a rough surface. Model a fair test by changing one factor at a time and measuring how far the car travels. Hand out the Forces Arrow Diagram Cards and ask students to match the cards to examples around the room. Keep the focus on identifying the direction of a push or pull rather than memorising terminology.

3. 12–22 minutes – Small-group force investigations Arrange students in two pairs, with roles of tester, measurer, recorder and equipment manager. Rotate roles halfway through. Distribute the forces investigation worksheet and guide students through three short tests:

• Push a toy car gently and strongly.
• Test the car on two different surfaces.
• Change the direction of the push. Students predict, test twice, measure or compare the distance, and record what happened. Use a timer and visual “first–next–last” prompts to maintain pace.

4. 22–27 minutes – Discuss findings and introduce simple machines Return to the simple machines teaching slides. Show how a ramp, lever or wheel-and-axle can help move an object by changing the direction of a force or reducing the effort needed. Use a classroom example, such as moving books with a ramp rather than lifting them. Ask each student to complete the sentence: “Our evidence shows that motion changes when…” Accept spoken, drawn or written responses.

5. 27–39 minutes – Design, make and test challenge Present the challenge on the design challenge instruction slides: “Design a simple machine that moves a toy or small object from the floor to a higher place, or across a difficult surface.” Provide cardboard, blocks, paper cups, paddle pop sticks, tape and toy cars or counters. Students sketch and label their idea on the worksheet, then build in pairs. Their design must use at least one ramp, lever or wheel. Test it twice, observe what happens and make one small improvement. Prompt with: “Where is the force?” “What is making movement harder?” and “What could you change without changing everything?”

6. 39–45 minutes – Share, assess and pack up Use the sharing and reflection slides. Each pair gives a 30-second explanation: what they built, what force they used, what happened and what they would improve. Invite the class to identify the simple machine in each design. Finish with the reflection prompts poster. Each student chooses one prompt and responds orally, with a drawing or in writing. Students return materials to labelled tubs and place worksheets in the collection tray.

Resources

• the forces and motion teaching deck
• the forces investigation worksheet
• the Forces Arrow Diagram Cards
• the reflection prompts poster
• Toy cars, counters or small classroom objects
• Cardboard, blocks, paper cups and paddle pop sticks
• Masking tape, string and rulers or metre rulers
• Smooth and rough test surfaces
• Visual timer and role cards
• Safety scissors, if required

Assessment

• Observe whether students correctly identify pushes, pulls, direction and changes in motion during testing.
• Check worksheets for predictions, recorded observations, comparisons and a labelled design.
• Listen to the final explanation for a correct link between the force, the simple machine and the movement produced.

Differentiation

• Provide a visual sequence, clear role cards, a timer and one instruction at a time; preview any changes to the routine for students with ADHD or Autism.
• Offer pre-cut materials, a choice of two design types and sentence starters such as “We pushed…”, “The friction was…” and “Next time we will…”.
• Allow students to demonstrate understanding through drawing, pointing, building or oral explanation rather than requiring extended writing.
• Extend confident students by asking them to compare two surfaces, include two simple machines or explain how their design changes the direction or size of the force.