BOAT: We chose the project to do the clay boats and hot air balloons. They float because of the density of air and buoyancy to float on the water. Buoyancy is the force equal to fluid...the weight of the displaced fluid. It is the upward force and keeps things floating. An object will float if the buoyancy is greater then the weight. We found the weight of the displaced fluid. We placed the boat in a container filled to the very top with water and formed a meniscus. When the boat was placed in the water, water spilled into a larger container and the this was the water the boat pushed out. Our little boat was 67.17 grams and the water it pushed out should have been equal to the boat. The water pushed out was 70 grams.
BALLOON:Denisty is: Mass/Volume Denisty is a physical property of matter that expresses a relationship of mass to volume. The denser, of two equal volume objects will be heavier. We made a hot air balloon with tissue paper, glue, templates and paper clips. We followed all the directions and created a balloon. We used the Indoor Balloon Tester and the pressure of the air pushing the balloon up made it float.
ARCHIMEDES: Archimedes Principle states:An object immersed in a fluid is buoyed up up by a force equal to the weight of the fluid displaced by the object. Knowing mass and volume of an object allows to calculate density.