- What do you know about water pressure? Air pressure?
- What do you know about buoyancy?
- What will you use to build your diver?
- Clean any labels off your pop bottle so you can see what is happening.
- Build your diver so that it floats vertically just below the surface of the water.
- There are a few ways to build your diver. One way is to attach a small piece of modeling clay to the end of a pen cap. There should be just enough clay that the pen cap floats just below the surface of the water.
- What other methods can you use to build your diver?
- Fill your empty bottle with water.
- Drop the diver into the bottle and screw the lid on tight.
- Give your bottle a squeeze. What happens?
- Control the motion of the diver by squeezing and releasing the bottle, forcing the diver to move up or down
- What do you know now that you did not know before?
- What happened to the diver when you squeezed the bottle? When you let go?
- What forces are acting on the diver?
- What do you think would happen if the diver was less heavy?
- How do you think this relates to a scuba diver?
- What elements of STEM are in this adventure? Science? Technology? Engineering? Mathematics?
- What did you like about this adventure? What did you not like?
- How would you do this adventure differently?
- 1 litre pop bottle and lid
- 5 mL eyedropper
- Something to use to make a diver, such as:
- An eyedropper
- A plastic pipette and a metal nut
- A pen cap with no hole and some modelling clay
Keep it Simple
- Try other things to see if they float. Try a stone, a feather, a bean etc.
Take it Further
- How does buoyancy work in submarines? Learn about how submarines work.