( II ) A railway track is laid at 11 degrees with 20 m long rails. What is the minimum space required between the ends of the rails if a maximum temperature of 33 degrees celcius is expected?

( III ) The central portion of the Pierre Laporte bridge is 667 m long. At each end of this steel structure is an expansion joint allowing a clearance of 21.9 cm. The average temperature in Quebec being 4 degrees celcius, what extreme temperatures can this construction withstand?

( V ) A steel rod with a radius of 2.1 cm, the ends of which are fixed, is subjected to a tension force of modulus 19 kN at both ends. What is the stress if the temperature (a) drops 10 degrees celcius; (b) rises 10 degrees celcius? (Young's modulus of steel is 2 x 10^11 N/m2^2.)