Science Experiment: Diving Jellyfish

Today, we are making a simple experiment with diving jellyfish in a bottle. It is also called a bottle diver. MATERIALS:⠀ - Paper straw - Paper clip - Empty plastic bottle - String - Water - Scissors - Permanent markers INSTRUCTIONS:⠀ (1) Cut about two inches long piece of paper straw, colour it with a permanent marker. (2) Thread a string through the straw and fold it in half. (3) Slide the straw over a paperclip so that two ends of a paper clip go inside two ends of the straw (4) Fill a plastic bottle with water. (5) Put your jellyfish in and close the cap. (6) Now squeeze the bottle to make the jellyfish sink and release to make him float again! SCIENCE EXPLAINED This experiment is about density. When we squeeze the bottle, we compress the air inside the straw. The air would keep the same mass, but now it would take up less volume, making it more dense, so the jellyfish sinks.