Description of activity
Students design and construct a functioning waterwheel.
This activity may take 1 hour or more depending on time allocated for discussion.
This lesson has two major goals. To provide the opportunity for students to:
- engage in a design process as they observe, design, and build a working model waterwheel
- compare the effectiveness of their models.
Knowledge and understanding
- Images depicting a variety of waterwheels
- Plastic plates, plastic straws, plastic cups, etc
- Masking tape, string, corks, wooden skewers, dowels, reusable putty
Work, health and safety
- Check relevant Work, health and safety guidelines.
- Highlight to students the need to be responsible and safe when using water.
- Be mindful of water spillage and slippery floors.
Evidence of work for assessment purposes
- annotated design plan for the waterwheel
- photo of the constructed waterwheel, which matches the design plan
- student evaluation of their design
STEM teaching and learning activities
- Recall that water is a major source of renewable energy.
- Describe how water is used in everyday life.
- Describe the advantages and disadvantages of using renewable energy sources.
- Look at various images of waterwheels and windmills.
- Students explain how they are similar and/or different.
- Students are challenged to design and build a model of a waterwheel that is turned by the flow of water. Parameters can be given, eg no larger than 30cm.
- Students research:
- How waterwheels work?
- What parts do they have?
- What do the paddles or blades of a waterwheel do?
- What features make efficient waterwheels?
- Students determine the purpose of their waterwheel, for example:
- turbine to generate electricity
- transfer or lift volumes of water.
- Students determine the number of paddles/blades and the angles needed for an effective waterwheel.
- Students determine ways to measure the effectiveness of their waterwheel.
- Students work in pairs to draw simple sketches of their ideas for a waterwheel. Label sketches justifying placement and use of materials.
- Students build and test their planned waterwheel. They may need to modify their design and rebuild the waterwheel until it works.
- Students take and record a series of measurements which determine the waterwheel’s effectiveness.
- Students compare their results with a waterwheel, designed for similar purpose, developed by another group. Discuss and record why there are differences and what contributes to those differences.
Hydroelectric power – captures energy from the movement of water (water’s kinetic energy) and converts it to electrical energy
Kinetic energy – the energy that an object has because it is in motion
Model – a small object, usually built to scale, that represents another, often larger object
Potential energy - stored energy
Renewable energy – energy collected from sources that are naturally replenished, eg solar, wind, geothermal, biomass, tidal and hydro (water)
Turbine – a device made up of a series of blades that is turned by a fluid (gas or liquid) and as it turns, transfers energy to a generator
Key inquiry questions
How are you going to record the details of your structure so that you or someone else can build it?
Scaled diagrams or diagrams with measurements of each component are the most accurate. Looking at a top view and a front/back view would be the most descriptive. (Application of the mathematical skills inherent in ST3-3D & 2D Space 1 & 2, Angles 1 & 2, Position)
What information would be important to make this an accurate record?
Examples include instructions, position of objects and details above.
The following statements outline some common preconceived ideas that many students hold, which are scientifically inaccurate and may impede student understanding.
That 'energy' and 'force' are the same thing
Energy is a tangible thing. A force is an action – a push or pull or twist.
Things 'use up' energy
Energy is never used up (law of conservation of energy), but it can change from one form to another (transformation of energy) or be transferred to another object.
If energy can never be 'used up' why do we need to conserve energy?
This refers to energy sources, eg coal or oil, which possess chemical potential energy. Once coal or oil is burned, this chemical potential energy is transformed into heat energy and there will be no more coal or oil.
Adjustments for the diversity of learners
Students investigate hydroelectric power.
- What is it?
- Is a hydroelectric power generator a modern-day interpretation of a waterwheel?
- Where are some of Australia’s hydroelectric power stations located?
- What is it about the location of these power stations that makes them suitable for generating hydroelectric power?
Students discuss the importance of water as a valuable resource.
- What would communities do without water?
- How can this precious resource is used wisely.
Compare and contrast waterwheels and windmills.
In this STEM activity, your students have investigated the conservation of energy incorporating the First Law of Thermodynamics that:
- the amount of energy in a system remains constant
- energy is neither created nor destroyed, it only changes from one form to another.
Your students will further develop this concept in Science Stages 4 and 5, physics and various technology courses.