Short Activity: Does Fruit Float?This simple activity is suitable for students of all ages when investigating buoyancy and applying real-world examples.

Activity ObjectiveStudents will explore the concept of buoyancy using everyday items.

Materials and Tools Buckets or tubs of water (rags to clean up spilt

water) A selection of fruit (pear, orange, banana, apple,

grape, lemon, lime etc.) Scissors/scalpels/instruments to cut or peel fruit

Activity OutlinePlease ensure you follow your school WH&S procedures while conducting this lesson.

It is recommended Step 2 of this activity is completed outside. If completed inside, ensure rags are used to clean up spilt water.

1. Introduce the question of “which fruit floats?” Ask why (no rights or wrongs here, just guesses!). Highlight the importance of buoyancy in real life applications, e.g. submarines (including the Deepsea Challenger which travelled to the deepest part of the ocean).

2. Explore! Provide pairs or individuals with a bucket of water and a selection of fruit, and challenge students to determine which fruits float or sink. Students can be encouraged to record their observations for discussion later.

3. After initial observations, ask students how they can manipulate the fruit to do the opposite to what was observed initially, and test their ideas. E.g. try peeling a banana/orange, or coring a pear.

4. Learn from the investigations by discussing as a group which fruits float and sink. Prompt discussion by asking: Why? How did you change the fruit to do the

opposite? What surprised you the most? Here you can discuss further the concepts of density, surface area, orientation, weight distribution etc., and relate to real life examples where possible.

Further InvestigationReal world examples include fish swim bladders, free diving, ice in water, and the impacts of water temperature on buoyancy (e.g. hot water vs cold water).

Some questions you may like to ask include: Why do some people float better than others? Does ice always float? E.g. in water, alcohol, oil etc. What’s so special about the Dead Sea? Why do heavy objects such as boats float? Why does melted land ice affect sea level but not melted sea ice? Why do NASA astronauts train underwater? How do fish swim bladders actually work? Why do objects seem lighter under water? What are the differences in the fruit tested?

Curriculum LinksOur resources provide a framework for classroom activities and lesson plans that link to the Australian Curriculum in both the Science, and Design and Technology streams. Some are highlighted below.

Science Inquiry Skills Science as a Human Endeavour

Science Understanding

Science Inquiry Skills are incorporated across all year levels by encouraging questioning and planning, planning and conducting, processing and analysing data and information, evaluating, and communicating.

If this activity is extended to research and discuss the applications of buoyancy, where and how it is used in society (e.g. boats, animals, nature), it links to the Science as a Human Endeavour Strand.

ACSHE120, ACSHE158, ACSHE228, ACSHE195

As well as investigating the physical forces of gravity, if this activity is extended to research and discuss motion, buoyancy and/or transfer of energy it links across various aspects of the Science Understanding Strand.

ACSSU043, ACSSU077, ACSSU117, ACSSU118, ACSSU150, ACSSU155, ACSSU175, ACSSU190, ACSSU229

Design and Technology Processes and Production Skills

Design and Technology Knowledge and Understanding

This activity provides hands-on engagement and skills and aligns with project management, design, and production with a strong emphasis on safety.

ACTDEP048

Facilitating discussion surrounding real life applications of technology, and the impact of cultural, financial, ethical and social factors on design can extend the scope of this activity to incorporate additional curriculum links.

ACTDEK043

If you have any questions regarding this teacher resource, contact the Smart Skills team at QSSI@questacon.edu.au, and connect with us on Twitter and Facebook.

If you would like to know more about our teacher professional development opportunities, contact the teacher professional development team at teachers@questacon.edu.au.