A disc of radius 50cm is such that its linear expansivity 'alpha' varies with the distance 'r' from its centre as alpha= alpha_(0) + alpha_(1) r where alpha_(0) = 1.8 xx 10^(-5)//°C and alpha_(1) = 1.2 xx 10^(-6)//m°C. Determine the increase in its surface area when heated through 40°C

A disc of radius 50cm is such that its linear expansivity 'alpha' vari

1.	A disc of radius 50cm is such that its linear expansivity 'alpha' varies with the distance 'r' from its centre as alpha= alpha_(0) + alpha_(1) r where alpha_(0) = 1.8 xx 10^(-5)//°C and alpha_(1) = 1.2 xx 10^(-6)//m°C. Determine the increase in its surface area when heated through 40°C
Answer» `18 PI MM^(2)` `180pi mm^(2)` `184 pi mm^(2)` `180pi CM^(2)` Answer :C