Awatermelon initially at 35": is to be cooled by dropping it into a lake at 15 =c. afterd h and 40 min of cooling, the centertemperature of watermelon is measured to be 20°c. treating the watermelon as a 20-cm-diameter sphere and using theproperties k= 0.618 w/m-k, a = 0.15 x 10—6 m2/s. p = 995 kg/m3. and cp: 4.18 kj/kg-k, determine the average heattransfer coefficient and the surface temperature of watermelon at the end of the cooling period.