LEGO bricks, despite being made of plastic, often float in water because they trap air within their hollow studs and internal structure. To make them sink, you need to systematically remove all the trapped air.
The Simple Trick to Sinking LEGOs
The most effective way to make LEGOs sink is to eliminate any air bubbles trapped inside them. This changes their overall density relative to water, allowing them to submerge.
Step-by-Step Guide to Making LEGOs Sink
Follow these steps to successfully sink your LEGO pieces:
- Submerge the LEGO Piece: Place the LEGO brick fully underwater in a container.
- Position Upside-Down: While submerged, hold the LEGO piece upside-down. This means the open end (where the studs would connect to another brick) should be facing downwards, allowing air to escape more easily.
- Tap to Release Air: Gently but firmly tap the LEGO piece against the side of the container of water. This action helps dislodge and push out any air bubbles trapped inside the brick's cavities.
- Observe and Repeat: Watch for small air bubbles escaping from the LEGO piece. Continue tapping and observing until no more bubbles are released. You might need to adjust the angle or tap multiple times.
- Achieve Sinking: Once you have successfully knocked every air bubble out of the LEGO piece, its overall density will increase, and it should sink to the bottom of the container.
Why LEGOs Float: Understanding Buoyancy
LEGO bricks are made from ABS (Acrylonitrile Butadiene Styrene) plastic, which is slightly denser than water. However, their intricate design, featuring hollow studs and internal cavities, traps air when submerged. This trapped air acts like a tiny air cushion, reducing the brick's overall density.
- Buoyancy: An object floats if it displaces a weight of water equal to its own weight. If the object's overall density (including any trapped air) is less than the density of water, it will float.
- Air's Role: Air is significantly less dense than water. When air is trapped inside a LEGO brick, it makes the combined "LEGO + air" system less dense than water, causing it to float.
- Sinking Solution: By forcing out all the trapped air, you remove the buoyant force created by the air. The LEGO brick, now filled only with water and its inherently denser plastic, will then have an overall density greater than water, causing it to sink.
For a deeper understanding of how objects float or sink, you can explore the principles of buoyancy and density further.
Practical Tips for Sinking LEGOs
- Use a Clear Container: A clear glass or plastic container makes it easier to see the tiny air bubbles escaping from the LEGO brick.
- Focus on Hollow Parts: Pay extra attention to larger, hollow bricks or those with more intricate internal structures, as these are more likely to trap significant amounts of air.
- Gentle Persistence: Some bricks might require more persistent tapping than others. Be patient and ensure no visible bubbles remain.
- Small Pieces: Very small or solid LEGO pieces might already sink or only float due to a minimal amount of surface tension or a tiny trapped bubble, making them easier to sink.
By following these methods, you can successfully make your LEGO bricks sink in water for experiments, play, or other purposes.
