Description of activity
Students design and build a vehicle with wheels that move. Determine which wheel and axle type is more efficient.
This activity will take 2 lessons:
- research and creating a design plan
- make, test, evaluate and modify the design
Friction is a contact force that will affect movement. Wheels are a way in which we can reduce friction thereby enabling more efficient movement.
Vehicles have wheels to make them move more easily. The wheels are attached by axles. Axles then need to be attached to a chassis. The chassis is the framework of the vehicle and attaches the axles and wheels to the body of the vehicle.
Knowledge and understanding
- Pictures of different types of vehicles
- A range of objects that could be used as wheels, eg toy wheels, plastic bottle tops, bobbins or cotton reels, cardboard discs, old CDs
- A range of objects that could be used as axles, eg straws, skewers, dowels
- A toy car that has been taken apart
- Sticky tape, masking tape, reusable putty, thumb tacks, low temperature hot glue
Work, Health and Safety
Check relevant Work, health and safety guidelines.
Hot glue may cause burns and may stick to the skin. Check for electrical safety each time before use. Test and tag at regular intervals.
Evidence of work for assessment purposes
- Two vehicles showing different wheel – axle arrangements
- Design plan including labelled diagrams justifying any modifications
- Description outlining how the vehicles were tested
- Conclusion explaining which vehicle was the most efficient
STEM teaching and learning activities
- Discuss the question 'What is a vehicle?'
- Students share their answers with each other. What types of vehicle were suggested?
- Look at pictures of different types of vehicles. Discuss the structures they all have in common. Students determine the main characteristics of a vehicle. Label images to indicate student responses.
- Focus on the picture of a car. Pose the question 'How does it move?' Students 'think, pair and share' their answers.
- Show the students an example of a toy car that has been taken apart. Students discuss what they can see. Explain the internal parts to the students and assign the names 'wheel' and 'axle'. Identify that the car also needs a chassis. Discuss the purpose of the chassis. What would happen if the car did not have a chassis?
- Demonstrate to the students how to put together a wheel and axle with the equipment you have prepared (dowels or straws, pre-cut wheels, cardboard disks or CDs)
- Demonstrate the two different types of wheels and axles (fixed and loose on a static axle)
- Discuss which materials could be used for wheels and why.
- Discuss which materials could be used for axles and why.
- Students make two different kinds of wheel and axle (fixed, where only the wheels move, and loose, where both wheel and axle move).
- Students develop a design plan to make a vehicle that will include wheels that move, including labelled diagrams of the two different wheel and axle types.
- Students build a fixed wheel-axle and a loose wheel-axle vehicle.
- Students test their vehicle to determine which they think is more efficient.
- Students justify their choice of vehicle.
Axle – a rod passing through the centre of a wheel
Efficient – functions in the best way with the least waste of time and effort
Justify – support an argument or conclusion
Machine – can change the direction or size of a force
Wheel – a circular object that revolves on an axle
Key inquiry questions
How do the features of this vehicle help meet its purpose?
Each structure/feature has a function/purpose. This is an important concept in all the sciences, eg materials and products, adaptations in biology.
What is the function of a wheel?
It reduces the area of contact between the object and the surface on which it is placed. This reduction in contact, alone, will reduce the amount of friction between the two surfaces. The fact that the wheel can rotate means that a smaller force can be applied to get it to move.
What is the function of an axle?
An axle is the central shaft of a rotating wheel. The axle may be fixed to the wheels, rotating with them, or fixed to the vehicle (chassis), with the wheel rotating around the axle.
How will you test your vehicles?
In order to determine which wheel-axle arrangement is more efficient the vehicles’ performances should be compared. Students devise their own testing method. Address issues around keeping it a fair test.
The following statement outlines some common preconceived ideas that many students hold, which are scientifically inaccurate and may impede student understanding.
Moving things stop because 'the push wore off'.
Children often know how to make things move or change shape but are not able to describe how the size or direction of the push, pull, twist or hit relate to the movement of the object. Stopping is generally thought of as being caused by the lack of a force/push. The slowing down or stopping of a vehicle is due to the force of friction acting in the opposite direction to the force of the push. If there were no friction the movement would continue, as it does in space.
Sometimes children will give the object human feelings, eg 'It stops because it gets tired' or 'it’s run out of energy'.
- YouTube video Wheel and Axle
- Wheely good wheels short student video
- Systems for Moving Things interactive information site for students
Adjustments for the diversity of learners
Investigate what happens when the axles are not at the centre of the wheels.
Does it make a difference if the material we use for our axle is long or short? Is a long-based axle better for movement than a short-based axle?
Test vehicles taking measurements of distance travelled, repeat the test several times, record results and find the average for each vehicle. These quantitative results can be used to further justify the student’s conclusion.
By completing this STEM activity students have been provided with opportunities to investigate variations in the structure of a machine and the way in which these variations affect their function. Helping students think about structure and function unifies many areas of learning and is a common concept across many curriculum areas and is particularly significant when studying Biology.
Your students were guided in the development and uses of a design plan, which is integral to any future studies in Technology. The planning and justification of changes to that plan develop critical thinking skills. Providing and receiving constructive feedback and making modifications to address issues raised develops student resilience and a culture of being able to learn from one’s mistakes.