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Question Number 141111 by jlewis last updated on 15/May/21
$$\mathrm{A}\:\mathrm{gap}\:\mathrm{must}\:\mathrm{be}\:\mathrm{left}\:\mathrm{between}\:\mathrm{steel}\: \\ $$$$\mathrm{rails}\:\mathrm{to}\:\mathrm{allow}\:\mathrm{for}\:\mathrm{thermal}\:\mathrm{expansion}. \\ $$$$\:\mathrm{How}\:\mathrm{large}\:\mathrm{a}\:\mathrm{gap}\:\mathrm{is}\:\mathrm{needed}\:\mathrm{if}\:\mathrm{the}\: \\ $$$$\mathrm{maximum}\:\mathrm{temperature}\:\mathrm{reached} \\ $$$$\:\mathrm{is}\:\mathrm{50}°\:\mathrm{above}\:\mathrm{the}\:\mathrm{temperature}\:\mathrm{at}\: \\ $$$$\mathrm{which}\:\mathrm{the}\:\mathrm{rails}\:\mathrm{were}\:\mathrm{laid}.\:\mathrm{The}\: \\ $$$$\mathrm{length}\:\mathrm{of}\:\mathrm{the}\:\mathrm{rail}\:\mathrm{is}\:\mathrm{10m}\:\mathrm{and} \\ $$$$\:\mathrm{the}\:\alpha_{\mathrm{steal}} =\mathrm{12}×\mathrm{10}^{−\mathrm{6}} /°\mathrm{c} \\ $$
Commented by mr W last updated on 15/May/21
$${in}\:{modern}\:{railway}\:{there}\:{is}\:{no}\:{gap} \\ $$$${in}\:{the}\:{rails}.\:{the}\:{rails}\:{are}\:{practically} \\ $$$${infinitely}\:{long}. \\ $$
Answered by TheSupreme last updated on 15/May/21
$$\mathrm{10}×\mathrm{12}×\mathrm{50}×\mathrm{10}^{−\mathrm{6}} =\mathrm{0}.\mathrm{006}{m}=\mathrm{6}{mm} \\ $$
Commented by jlewis last updated on 15/May/21
$${wah}!!{just}\:{as}\:{simple}\:{as}\:{this}??{anyway}\:{thanks} \\ $$