In a die-casting of aluminium, heat transfer is limited by the metal-mould interface, which has a heat transfer coefficient k 2.1 kj m2 k-1 s-1 the following values apply 933 k melting temperature of aluminium, t density of solid aluminium, ps=2700 kg m- latent heat of fusion of aluminium, hm 390 kj kg- = given that the thickness of solid aluminium after 10 s is 1.29 cm, use the equation for interface resistance limited solidification k(t-to) s t. pahm to calculate: (0) the gradient of a graph of s against t, in ms1, to 3 significant figures (u) the temperature of the mould in c, to the nearest degree (take 0 c 273 k) gradient of s against t: ms to 3 s f temperature of mould oc to nearest degree