4. Density of foodstuff can be determined using the following equation: p= Xp + + Pw Pp 1 X X + + Pf Pc Pa Where: p= density of foodstuff (g/cm3) 1 pw = density of water = 1.0 g/cm3 Pp = density of protein = 1.4 g/cm3 pt = density of fat = 0.9 g/cm3 pe = density of carbohydrates = 1.5 g/cm3 Pa = density of ash = 2.16 g/cm X = mass fraction, decimal Calculate the: a) specific heat (J/kgC, 1 mark); b) thermal conductivity (W/mC, 1 mark); and c) thermal diffusivity (m/s, 2 marks) of Cheddar cheese having the following composition: Water = 37% Protein = 25% Fat = 32.2% Carbohydrates = 2.1% Ash = 3.7% Total 100%