A blacksmith heated a metal whose cubic expansivity is 3.9 x 10\(^{-6}\)K\(^{-1}\). Calculate the area expansivity.
A
3.9 x 10\(^{-6}\)K\(^{-1}\)
B
2.6 x 10\(^{-6}\)K\(^{-1}\).
C
1.3 x 10\(^{-6}\)K\(^{-1}\).
D
1.6 x 10\(^{-6}\)K\(^{-1}\).
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
3\(\alpha\) = \(\gamma\)
\(\alpha\) = \(\frac{3.9\times 10^{-6}}{3}\) = 1.3 x 10\(^{-6}\)
BUT \(\beta\) = 2\(\alpha\)
\(\beta\) = 2 x 1.3 x 10\(^{-6}\) = 2.6 x 10\(^{-6}\)K\(^{-1}\)
Source: WAEC / JAMB / NECO Classroom Archive (Record #70661)