Lesson 1: Density and the Rising Molecule
Duration of Days: 2.5
Lesson Objective
Students will explain the relationship between air temperature and density to predict how a temperature differential creates buoyant force.
1. Why does heating air molecules make them take up more space?
2. How does the "weight" of the air inside the balloon compare to the air outside?
Density, Kinetic Molecular Theory, Temperature Differential, Buoyancy, Ambient Air.
ENG.01.01: Explain principles of aerodynamics/fluids.
NGSS HS-PS3-2: Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motions of particles.
Students observe a "Density Bottle" demonstration (cold vs. hot water with food coloring) to visualize fluid movement. They use a digital thermometer to measure the air coming out of a heat gun vs. the classroom air.
Purpose: To build the conceptual "why" before students begin the labor-intensive construction.
DOK Level: Level 2 (Skills & Concepts).
Provide a visual "Molecular Movement" graphic organizer for students to draw the density of air at 20°C vs. 180°C.
Assessment of Understanding: Exit Ticket: "If the classroom is 70°F and the balloon air is 150°F, will the balloon have more or less lift than if the classroom were 40°F? Explain."
Heat guns, digital thermometers, "Science of Flight" introductory text, clear containers for water density demos.