EPE Type Experiences
(Observations,
Data)
Student Personal Everyday experiences with floating and sinking
Impressions of weight
Comparing amounts of liquids by pouring
Scientific
Qualitative
Scientific
Quantitative
Comparing mass and density: Systematic observations of floating and sinking, varying volume, mass and density of solids and liquids
Measurements of weight and volume of different materials to calculate density
Measurements of weight of objects suspended in fluids
Measurements of pressure at different depths in fluids
Patterns
(Generalizations,
Laws)
Objects have two general properties: heaviness and amount
Gases weigh less than liquids and solids
Heavier objects sink, light objects float
Air does not make heavy objects float
Weight/mass, volume, and density are separate properties
Whether objects or fluids float or sink depends on relative densities
D = m/v
Archimedes’ principle: Buoyant force equals volume of object times density of medium.
(Weight equals volume of object times density of object.)
Application
Inquiry
Explanations
(Theoretical
Models)
Floating and sinking and balances both compare “heaviness” of objects/materials
Buoyant force is caused by difference in pressure on the top and bottom of an object (or part of fluid)
Pressure equals weight of fluid above the point where it is measured