If heavier objects sink and lighter objects float, then just want did we do to make the LEGO sink and float. Well, he didn’t sink and float at the same time! There were times when he floated near the top of the plastic container and other times he sank. We had fun exploring this cool science challenge.ain the Cool Science
When we squeezed water filled bottle that the LEGO man was in, we pushed water into the straw he is wearing on his back. This made our LEGO man heavier. The density went up and that made him go down.
When we let go of the bottle, the pressure of the air in the straw pushed the water out of the straw. The LEGO man was less dense and so he floated or bobbed back to the top of the bottle.
How Did We Get Our LEGO Man Ready for the Experiment
- LEGO man
- Large paperclip
- Fishing line
- Small Washer
- Plastic container with a large mouth (We used an old peanut container.)
First cut a bendy straw so that we had about 3 inches on either side of the bendy section.
Then slide the straw over the two ends of the paper clip.
Next we tied the straw onto the paper clip to the LEGO man with fishing line.
Then we tied a small washer to the rounded end of the paper clip. The washer added just enough weight to the LEGO man. It helped him floated just above the bottom of the container.
Conducting the Cool Science Sink or Float Experiment
We placed the LEGO man with a straw and paper clip backpack and a washer into the plastic container filled with cold water.
Then we screwed the lid on tightly.
Next we squeezed the plastic container with one or two hand. ( I used one hand and JDaniel needed two hands)
The LEGO Man sometimes slowly and other times quickly shot up in the plastic container.
Hint: We tried this experiment with warm water and the LEGO man sometimes did the opposite actions. You may want to try water of different temperatures too. It didn’t happen every time. I wonder why?