A Little Beach DIY
Two people are on the beach, one in a bright yellow life jacket and the other with a makeshift floatie. The man has 1.5-liter soda bottles tied around his stomach and back. Will this make him float? Yes, it will! The science behind this involves buoyancy.
When empty, soda bottles are filled with air, making them less dense than water. This lower density allows them to displace more water, providing lift and making the person float. Buoyancy is the principle that objects will float if they displace an amount of water equal to their weight. While not as reliable as a life jacket, this can help keep him afloat!