Data: ΔT = 30 °C – 15 °C = 15 °C, l1 = 324 m, λ for iron = 11.5 × 10-6 /°C l2 – l1 = λl1 ΔT
= 11.5 × 10-6 /°C × 324 m × 15 °C
= 55890 × 10-6 m
= 55890 × 10-6 × 102 cm
= 55890 × 10-4 cm
= 5.589 cm (nearly 5.6 cm)
This is the increase in the length, i.e., the increase in the height of Eiffel Tower.