A common trick to open the lid of a jar that is stuck is to put the lid under hot running water. Suppose the diameter of the lid of a jar of strawberry jam is 6 cm. By how much does the circumference change if the temperature is increased by 30°C? Assume the lid is made of steel.

Question

Quizplus · Accepted Answer

The change in circumference can be calculated using the formula ΔC = C₀αΔT, where C₀ is the initial circumference, α is the coefficient of linear expansion for steel (approximately 11 × 10⁻⁶ /°C), and ΔT is the change in temperature. The initial circumference C₀ = π × diameter = π × 6 cm. Plugging in the values, ΔC ≈ 6.2 × 10⁻³ cm.

A Common Trick to Open the Lid of a Jar