Question:
A glass window is to be fit in an aluminium frame. The temperature on the working day is $40{ }^{\circ} \mathrm{C}$ and the glass window measures exactly $20 \mathrm{~cm} \times 30 \mathrm{~cm}$. What should be the size of the aluminium frame so that there is no stress on the glass in winter even if the temperature drops to $0^{\circ} \mathrm{C}$ ? Coefficients of linear
Solution:
