A sheet of glass measures one metre by half metre at 0°C. Calculate its area at 30°C, a for glass = 0.000009°C-1.

0.50027

Explanation:

ΔA=

Where ΔA is the change in area

There is a 2 since the coefficient for area = 2 x that for the linear coefficient

is the original area

is the coefficient of thermal expansion

And T is the change in temperature

ΔA=2(0.000009)(0.5)(30-0)=0.00027

New area= ΔA+ = 0.5+0.00027=0.50027