A 40g ring was purchased, knowing the density of pure gold is 19.3 gcm^-3 determine if the ring is pure gold if the ring displaces 2.6cm3 of water when submerged. Explain your reasoning

wher is the rest of the question

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.