We decided to show Santa a pumpkin today because it is Halloween tomorrow.
We passed the pumpkin around our circle and all gave an adjective to describe what the pumpkin looked or felt like.
After that, Miss Yarrow revealed a tub of water and said that we were going to do some pumpkin science as well. She asked us to predict if we thought the pumpkin would float or sink? Most of us thought the pumpkin would float. We tested to see if our predictions were accurate; the pumpkin bobbed on the top of the water, which meant that it was floating! (If it had sunk, it would have dropped to the bottom of the basin). Miss Yarrow told us that there was a scientific word for floating and that word is buoyancy and we can say that things are more or less dense than other things. So, instead of saying that the pumpkin floated in the water, we could say that the pumpkin was buoyant in or less dense than water.
We discussed why this might be the case. One of us suggested that its because there isn’t ‘stuff’ filling up the inside and that there’s space in it. Miss Yarrow explained that was in fact correct, and that because pumpkins are hollow, they have air in them, which makes them float/less dense. It didn’t matter that the pumpkin felt heavy to us (boats are heavy but they float in the ocean).
Next, Miss Yarrow asked us to ‘gut’ our pumpkin. We loved getting messy and taking the pumpkins insides, out. We got rid of the flesh and kept the seeds for our next experiment. We made new predictions about whether the seeds would be more or less dense than water. This time, most of us thought they would be more dense and that they would sink. We believed this because we thought that the insides were full up this time and not hollow. However, when we tested them, they all stayed floating on the surface too.
We each took a pumpkin seed home with us to remind us of today’s learning.
Santa was impressed with our topical science. He learned a lot about pumpkins and buoyancy!
