a copper bar is to be inserted between two rigid blocks as shown in the figure. the copper bar was fabricated $2$mm shorter than the $1\mathrm{.}5$m gap between the blocks. in order to get the bar into the gao it will be heated. what increase in temperature is required to allow the bar to fit in the gap? once the bar is in the gap and fixed in place, it is allowed to cool to its original temperature. what will be the resulting axial stress in the bar? indicate whether the stress is compressive or tensile.