Question

The coefficient of linear expansion of iron is 1.0 × 10−5 per C◦ . The surface area of an iron cube, with an edge length of 5.0 cm, will increase by what amount if it is heated from 10◦ C to 60◦ C?

Answer 1

The linear expansion of iron is a = 1× 10∧ -5 /°C
Length edge is 5cm
Initial surface area of cube A = 6L ∧²
 = 150cm∧²
The edge length of cube after being heated from 
10°C to 60°C is
L = L[I +a dt] where the dt is = 60-10 = 50°C
5.0025cm
A surface area of the cube after heated is 
A' = 6L' ∧²
= 150.1500375 cm∧²
The increased area is = A' -A = 0.15cm∧²