Linear, Superficial, and Cubical Expansion Puzzles
Explore the concepts of linear, superficial, and cubical expansion with these puzzles. Click the buttons to reveal hints and answers!
Puzzle 1: What does the coefficient of linear expansion measure?
It’s related to changes in length.
It measures how much a material’s length changes per degree of temperature change.
Puzzle 2: How is the coefficient of superficial expansion different from linear expansion?
Superficial expansion involves an area.
The coefficient of superficial expansion measures the change in area, while linear expansion measures the change in length.
Puzzle 3: What is the relationship between the coefficient of linear expansion and superficial expansion?
Think about dimensions.
The coefficient of superficial expansion is approximately twice the coefficient of linear expansion (β = 2α).
Puzzle 4: How is the coefficient of cubical expansion related to linear expansion?
Cubical expansion involves volume.
The coefficient of cubical expansion is approximately three times the coefficient of linear expansion (γ = 3α).
Puzzle 5: Why do engineers use the coefficient of cubical expansion for liquids?
Liquids expand in three dimensions.
Since liquids expand in volume, the coefficient of cubical expansion is used for their thermal expansion calculations.
Puzzle 6: If a metal plate has a hole, what happens to the size of the hole when the plate is heated?
The entire plate expands uniformly.
The hole also expands as the metal plate expands, maintaining its shape.
Puzzle 7: Why does glass crack when subjected to sudden temperature changes?
Glass has low thermal conductivity.
The uneven expansion caused by sudden temperature changes creates stress, leading to cracks.
Puzzle 8: A rod of length 1m expands by 1mm when heated by 100°C. What is its coefficient of linear expansion?
Use the formula: ΔL = α × L × Î”T.
α = ΔL / (L × Î”T) = 1 × 10⁻³ / (1 × 100) = 1 × 10⁻⁵ °C⁻¹.
Puzzle 9: Why does the coefficient of expansion for gases differ from solids?
Gases expand freely in all directions.
Gases expand much more than solids due to the lack of strong intermolecular forces.
Puzzle 10: What happens to the density of a material as it expands?
Density is mass per unit volume.
The density decreases as the material expands, since the volume increases while the mass remains constant.
