Refinement of Quantitative Experimental Teaching Materials for Learning Buoyancy, Based on the “Ishi-tsuri Bune” Model: Toward the Use of Existing Materials in Upper Secondary School

Abstract

This study aimed to refine the “Ishi-tsuri Bune” model teaching material proposed in previous research to quantitatively capture the principle that “the volume of an object submerged in water determines the magnitude of buoyancy” in buoyancy learning. With upper secondary school usage in mind, the teaching material was developed to enable quantitative prediction of the maximum number of stones a boat can carry based on the mass and volume of both the boat and the stones, followed by empirical verification. The validation results of the developed material demonstrated that the maximum number of stones the boat could carry generally matched the predicted number, confirming its utility as a teaching material to effectively convey the concept that “the volume of an object submerged in water determines buoyancy.” However, when the stones were suspended below the boat, the most frequent result was one stone fewer than the predicted maximum carrying capacity, differing from the results when the stones were placed on top of the boat. This discrepancy was attributed to the tilting of the boat caused by a shift in the overall center of gravity.