Question 3 (TOTAL 8 marks) A sphere of radius 10 mm at a temperature of 600 K is dipped into the liquid at 300 Kelvin with a convective heat transfer coefficient of 100 W mK-!. The specific heat capacity and thermal conductivity of the sphere is 375 J kg 'K- and 360 W m-'K', respectively, and its density is 8700 kg m Find the time required to become temperature of the sphere equals to 500 K 18 marks