# Submarine buoyancy investigation

#### Lesson overview

This lesson encourages students to investigate hands-on the property of neutral buoyancy, and to discuss its importance in terms of submarines.

There is a practical investigation to achieve neutral buoyancy for a floating object by adding weight. This session also explores the mathematics of density and buoyancy.

#### Learning outcomes

• Describe how to make floating objects sink (foundation)
• Make an object neutrally buoyant through experimentation (developing)
• Explain how neutral buoyancy is achieved in terms of forces (competent)
• Calculate the density of a spherical object (expert)
• Calculate the weight required to make a floating object neutrally buoyant (advanced)

#### Lesson steps

1. Brief (15 mins)
Students view 360VR panoramas of a submarine dive and answer questions, before being introduced to the aim for this lesson, creating a submarine that is neutrally buoyant. Students set themselves targets based on the intended learning outcomes for the lesson.
2. Investigation (20 mins)
Students follow the investigation brief to try to make their ping pong ball neutrally buoyant. Students are encouraged to adapt to their results, and make changes as they go.
3. Calculating neutral buoyancy (15 mins)
Using the slides, students learn how an object becomes neutrally buoyant in terms of forces and displacement. Students calculate the amount of mass needed to make their ping pong ball neutrally buoyant, and conduct the experiment to see if their calculations matched the result obtained. Advanced students may wish to calculate this before their experiment.
4. Summary conversation (5 mins)
Students demonstrate their learning by tweeting a summary of the lesson, or making an Instagram post.
5. Self-reflection (5 mins)
Students decide if they have met their targets set at the beginning of the lesson, and reflect on the lesson’s importance to the context of the overall unit of work.