A boy wants to mix up 500 grams of cake batter for his self-made chocolate cake. 100 Watts of mechanical energy is produced by the mixer and is transferred into heating up the cake batter. The cake batter has an average heat capacity of 2800J/kg.°C and has a temperature of 7°C, before mixing. We assume thatLa reacc the cup with batter is insulated quite well and that, for such short times, no heat transfer takes place with the environment.