1its okay if you are desperate but theres no point in starting two threads for same question
if its your doubt
did you try to get the result by differentiation?
3 Answers
11consider a square plate of a material whose coeficent of linear expan.is α
and that of superficial exp. is β.let the increase in temp be Δt
let original each side of square be a and the area be A
new length after increase in length = a(1+αΔt)
new area after increase in length = a2(1+αΔt)2
= a2(1+2αΔt)..(1)
new area = A(1+βΔt)...(2)
now A = a2
comparing (1) and (2) we get
β = 2α
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