Question

A square plate of side 12cm is made of metal of linear expansivity 2*10-5 k as the plate is heated from 30degree c to 100degree c , the area of one of the face of the plate will increase to ?

Answer 1

$a'=a(1+\alpha \Delta t)=12.0168~cm,$

$A'=a'^2=144.4~cm^2.$