This is a great activity in many ways, I particularly like how it built on the concepts of volume and density which students already knew. This activity allowed my students to test Archimedes’ principle through a simple activity. Many students are now interested in knowing more on designing of boats.
-Class 9, Physics teacher
We conducted this activity in class 9 to build the concept of Buoyancy. This is an inquiry-based activity in which students worked together as a group to solve the given problem. The activity intended to improve students’ observation skills, analysis skills and application skills.
Initially students were posed with a design problem related to building of boats. This problem made them curious about how boats float and the relation between fluid force, volume and density. At this stage, they were introduced to the concepts of Buoyancy and Archimedes’ principle. This hands-on activity helped them to test the principle and arrive at conclusions.
Hands-on activity- Archimedes’ principle
After completing the activity students discussed in a group and compared their data with other groups and concluded the following
- When an object is immersed fully or partially in the water or any fluid, it displaces some water or fluid and experiences upward thrust equal to the weight of the displaced water or fluid.
- The volume of the displaced water is equal to the volume of the object.
- When the weight of the displaced water is less than the weight of the object then the object sinks. When the weight of the displaced water is more than the weight of the object then the object floats.
- The objects which are denser than water, can be a floater or a sinker, depending on their shape.
- A huge boat will float because it displaces a huge amount of water that weighs more than the boat. When we start adding weights into the boat it begins to sink and it will continue to sink into the water until the weight of the water that the sinking boat displaces is equal to the weight of the boat.