Your homemade hot air balloon won't fly into the air I'm afraid but it will be a great chance to learn about how temperature makes air expand and is great fun too. Plus all you need is a balloon, plastic bottle and a pint glass to get started!
What do I need:
- A plastic bottle
- A pint glass
- A balloon
How do I do it?
STEP1 - Let's get going! Half fill your pint glass with very hot water (Make sure you've got adult supervision for this one!)
STEP2 - Next up, pop your deflated balloon over the top of your bottle, as shown.
STEP3 - Now to fill your hot air balloon up! Submerge the bottle into the glass of hot water and now the waiting begins...Slowly but surely your hot air balloon will start to fill up!
What's going on?
It's all to do with the expansion of air. When you first put the balloon over the top of the bottle the air inside is at regular air temperature. Once that bottle is submerged in the hot water the air inside the bottle starts to heat up. As the air gets hotter those air molecules get more and more energy and the air expands and blows up you hot air balloon!
More Fun Please - Experiment like a real scientist!
- Does the temperature of the water change how big your balloon gets?
- Does this experiment work again and again?
- What do you need to do to repeat this experiment?