Chapter 10 - Temperature and Kinetic Theory - Learning Path Questions and Exercises - Exercises - Page 384: 40

Fraction change in area: $0.00792$ Percentage decrease in area: $0.792$

We know that fraction change in area is given as $\frac{\Delta A}{A}=2\alpha \Delta T$ We plug in the known values to obtain: $\frac{\Delta A}{A}=2\times 12\times 10^{-6}\times (-330)=0.00792$ Now the percentage decrease in area is given as $\frac{0.00792\times 100}{100}=0.792\%$