An metal rod heated from 30°C to 80°C. The final length of the metal is 115 cm and the coefficient of linear expansion is 3 × 10⁻³ K⁻¹. What is the…
Source: JAMB · 2024
An metal rod heated from 30°C to 80°C. The final length of the metal is 115 cm and the coefficient of linear expansion is 3 × 10⁻³ K⁻¹. What is the original length and the change in length of the iron?
Explanation
Linear expansion: L = L₀(1 + αΔθ). The temperature rise is 80 − 30 = 50 K.
αΔθ = 3 × 10⁻³ × 50 = 0.15. So 115 = L₀ × 1.15.
Original length L₀ = 115 ÷ 1.15 = 100 cm.
Change in length = 115 − 100 = 15 cm. The answer is 100 cm, 15 cm.
Was this explanation helpful?
Something wrong or missing? Tell us — we read every report and fix issues fast.