Floating challenge!

Once again, we've been busy researching and testing the science behind why boats and objects float in water. We quickly discovered that a ball of plasticine will sink in water. It's weight is focused in small amount of space. Because the ball has a small surface area, the upthrust acting upon the ball was unable to push it back up to the surface. Gravity was more powerful than the uphrust so it sank!

 

We were then set a challenge.... using the same ball of plasticine, could we change the shape to make it float? There was a vast array of designs and some were more successful than others!

 

Some tried creating shapes that had pocket of air inside them. Sadly, there wasn't enough to keep them afloat!

 

Others tried making holes to try and trap air. However, the plasticine was so compacted that the air was pushed out of the shape and it sank as the water pushed through.

 

This group tried using a leaf shape as they knew leaves floated on water. Sadly, the water splashed over the sides and made it heavier so it sank!



There were other ideas from our knowledge of the world too - some groups tried using raft designs and fish because they knew they could float in water. However, they didn't quite work!

 

Success! Rosie and Chaithanya's flower design and Morgan's bowl shape were the first to float! They manage to make the force of gravity and upthrust BALANCED.