Steel rails for a railway track are each 10.0 m long at 5 °C
PHYSICS · Multi-part · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
Steel rails for a railway track are each 10.0 m long at 5 °C. The highest temperature expected in that region is 45 °C. The coefficient of linear expansion of steel is 1.2×10−5K−1.
(i) Calculate the increase in length of one rail when the temperature rises from 5 °C to 45 °C.
(ii) Determine the minimum gap that must be left between successive rails at 5 °C so that no buckling occurs at 45 °C.
(iii) If construction constraints limit the gap to 3 mm at 5 °C, up to what maximum temperature can the track be safely used without the rails pressing against each other?