A blacksmith heated a metal whose cubic expansivity is 6.3 x 10-6K-1. The areal expansivity is

A blacksmith heated a metal whose cubic expansivity is 6.3 x 10-6K-1. The areal expansivity is

Answer Details

If the lineal expansivity = ∝
=> area expansivity β= 2∝.
And cubic expansivity δ = 3∝.
=> 6.3 x 10-6 = 3∝
∴ ∝ =