We took our homeschool science curriculum on the road today for a special hands-on lesson at Grandma’s house! Turning the pool into a temporary testing lab, we dove into Lesson 30: Float or Sink from our The Good and the Beautiful Sparks and Stars science book.
Before getting our hands wet, we sat down with the lesson text to talk about the core mechanics of physics:
- Density: We looked at how closely packed an object’s building blocks (molecules) are. If an object is less dense than water, it stays on top. If it’s more dense, down it goes!
- Water Displacement: We learned that whenever an object sits in water, it pushes some of that water out of the way. If the object weighs less than the amount of water it displaces, it floats perfectly.
- Weight vs. Shape: We discussed how weight isn’t the only thing that matters—even massive ships can float if their shape displaces enough water!
The Engineering Challenge: Upcycled Sailboats
To bring these concepts to life, we gathered some simple household recycling and craft supplies to engineer our own vessels:
- Empty plastic water bottles (our pontoons)
- Rubber bands to tie the hulls together
- Bamboo skewers for the masts
- Construction paper, crayons, and markers to design custom sail
We wanted to test how the design of a boat impacts its stability and floating ability. We engineered two distinct styles to see how they compared: a single-mast boat and a double-mast boat.
The Results: Which Design Sailed Best?
We launched both ships from the shallow steps of the pool to see how they held up.
Because the plastic water bottles are filled with air, they are incredibly low-density, meaning both designs floated perfectly on top of the water without sinking. However, when it came to actually navigating the water, the double-mast boat performed much better!
While the single-mast boat kept its balance, the double-mast boat caught the breeze beautifully, sailed across the pool with much better balance, and proved to be the superior design for our afternoon testing. It was the perfect blend of physics, creative engineering, and outdoor fun. A huge thank you to Grandma for letting us turn her pool steps into a scientific testing ground!
What about you? Have you ever tried building upcycled boats with your family? What everyday materials have you found work best for keeping homemade ships upright? Let us know in the comments below!
Check back soon for more of our hands-on learning adventures here at the Sea Garden House!
Leave a Reply