Question

Calculate the stress developed inside a tooth cavity filled with copper when hot tea at temperature of 57^oC is drunk. You can take body (tooth) temperature to be 37^o C and α = 1.7× 10^-5/^oC, bulk modulus for copper = 140 × 10 ⁹ N/m².

Answer 1

Stress = K × strain

= K(ΔV/V)

=K(3α)Δt

= 140 x 10⁹ x 3 x 1.7 x 10^-5 x 20

= 1.428 x 10⁸ N/m² 

This is about 10³ times atmospheric pressure