Question 3

A solid 30x30mm square beam with a length L=1.2 m is supported by a pin and roller. There is a 0.4mm gap between the beam and an adjacent rigid wall when the temperature is 10°C.

a) if the temperature is raised to 45°C, and the wall is removed so that the beam is unrestrained, what would be the change in the beam length in mm? 

Assume E_st = 200GPa, α_st = 12x10^-6/ºC. 

A negative sign indicates shortening. Do NOT include any units.

Give the answer to 2 decimal places.