A thin aluminum plate has a surface area of 1.500m at 20ºC. What will be its surface area when it is cooled to -20ºC? (Take the linear expansivity of aluminum to be 2.5 x 10-5k-1).
A
1.503m2
B
1.500m2
C
1.498m2
D
1.497m2
E
1.490m2
Verified Correct Answer: D.
Physical Principles & Numerical Solution
\(\beta\) = 2\alpha
2 X2.5 x 10-5 = \(\frac{A_2 - 1.5}{1.5 \times (-20 -20)}\)
\(A_2 - 1.500\) = - 0.003m
\(A_2\) = - 0.003 + 1.500 = 1.497\(m^2\)
Source: Myschool Past Questions Archive (Record #28582)