MC · 8 cards

Heat, Materials and Expansion flashcards

8 cards with the formulas, rules and traps from this lesson. Answer in your head, then flip to check.

Term · 1/8
Temperature vs. heat: what is the difference?
Temperature measures how hot something is (average particle motion), in °C or K. Heat is energy (joules) transferred because of a temperature difference, always flowing from hot to cold.
Formula · 2/8
How do you convert Celsius to Kelvin and to Fahrenheit?
$T_{K} = T_{C} + 273.15$ and $T_{F} = \frac{9}{5} T_{C} + 32$ . For changes, 1°C = 1 K and 1°C = 1.8°F (a 10°C change is an 18°F change, no 32 added).
Formula · 3/8
Linear thermal expansion formula
$Δ L = α L_{0} Δ T$ : α is the expansion coefficient (1/°C), $L_{0}$ the original length, $Δ T$ the temperature change. A 25 m steel rail (α = 12 × 10⁻⁶/°C) warmed 40°C grows 12 mm.
Common trap · 4/8
When a metal plate with a hole is heated, what happens to the hole?
The hole gets bigger. Every dimension grows by the same fraction, like enlarging a photo, so holes, ring bores and gear bores all expand.
Term · 5/8
Name and define the three ways heat is transferred
Conduction: through a material by particle contact. Convection: carried by a moving fluid (natural or fan-forced). Radiation: electromagnetic waves, which can cross a vacuum.
Formula · 6/8
Heat needed to change temperature without a phase change
$Q = m c Δ T$ : Q in joules, m in kg, c specific heat in J/(kg·K), $Δ T$ in °C or K. Water's c is about 4,200 J/(kg·K), far higher than most metals.
Formula · 7/8
Energy for a phase change (melting or boiling)
$Q = m L$ , with L the latent heat in J/kg; temperature stays constant during the change. Water: fusion about 334,000 J/kg, vaporization about 2,260,000 J/kg.
Formula · 8/8
Define stress, strain and Young's modulus
Stress $σ = F / A$ (Pa); strain $ε = Δ L / L_{0}$ (no unit); Young's modulus $E = σ / ε$ measures stiffness (steel about 200 GPa, aluminum about 70 GPa).

← Springs and Elastic Systems Spatial Orientation Basics →