Archimedes Squeeze Experiment - Density values over 1g/cm3 not sinking?
Posted: Mon Mar 21, 2022 2:17 am
Hi there
Question re Archimedes Squeeze experiment https://www.sciencebuddies.org/science- ... -boat-sink which my daughter tried at home.
When she did the experiment, the foil ball with a diameter of 2.8cm sank, with the longer diameters ranging on average from 10% submerged for 6cm, to 64% submerged for 4cm diameter to 90% submerged for 3cm. That all seems very explainable with regards to the % submerged increasing as the diameter decreased, and the resulting volume decreased and the corresponding density increased.
The query relates to the actual density values calculated based on the reducing diameter measurements. The density values where nearly all greater than 1g/cm3, the density of water. eg 4.5cm diameter had a density of 1.13g/cm3, 3.5cm equated to 1.46g/cm3 and the 3cm equated to 1.70g/cm3 - yet none of these balls sank but ranged in % submerged from 40% to 90%. The 2.8cm diameter sphere sank with a density of 1.82g/cm3. She expected that the spheres with a density greater than water would sink? Is partial submerging expected with densities greater than water? What explains the tipping point of the ball sinking when the density value reached earlier in the experiment was already greater than that of water. As the experiment is limited with regards to approximate diameter values as balls were not uniformly uniform, she understands values are not fully accurate. She (and I) just want to understand more what is going on to explain to actual experimental results. Overall, the experiment demonstrates well how increasing density decreases buoyancy. Is the presence of air captured in the ball a contributing factor to how quickly the ball sinks, and impacts the actual calculated density of each of the balls/spheres? Are there other factors at play?
Hope the above is clear and really appreciate any thoughts/explanations.
Many thanks
Question re Archimedes Squeeze experiment https://www.sciencebuddies.org/science- ... -boat-sink which my daughter tried at home.
When she did the experiment, the foil ball with a diameter of 2.8cm sank, with the longer diameters ranging on average from 10% submerged for 6cm, to 64% submerged for 4cm diameter to 90% submerged for 3cm. That all seems very explainable with regards to the % submerged increasing as the diameter decreased, and the resulting volume decreased and the corresponding density increased.
The query relates to the actual density values calculated based on the reducing diameter measurements. The density values where nearly all greater than 1g/cm3, the density of water. eg 4.5cm diameter had a density of 1.13g/cm3, 3.5cm equated to 1.46g/cm3 and the 3cm equated to 1.70g/cm3 - yet none of these balls sank but ranged in % submerged from 40% to 90%. The 2.8cm diameter sphere sank with a density of 1.82g/cm3. She expected that the spheres with a density greater than water would sink? Is partial submerging expected with densities greater than water? What explains the tipping point of the ball sinking when the density value reached earlier in the experiment was already greater than that of water. As the experiment is limited with regards to approximate diameter values as balls were not uniformly uniform, she understands values are not fully accurate. She (and I) just want to understand more what is going on to explain to actual experimental results. Overall, the experiment demonstrates well how increasing density decreases buoyancy. Is the presence of air captured in the ball a contributing factor to how quickly the ball sinks, and impacts the actual calculated density of each of the balls/spheres? Are there other factors at play?
Hope the above is clear and really appreciate any thoughts/explanations.
Many thanks