Two samples of liquid water are mixed in a perfectly insulated container

PHYSICS · Subjective · AP · Physics 2: Algebra-based · Thermodynamics · Thermodynamics

Problem

Two samples of liquid water are mixed in a perfectly insulated container. Sample A has mass

100\,\text{g}

80\,^{\circ}\text{C}

, and Sample B has mass

200\,\text{g}

20\,^{\circ}\text{C}

. Calculate the equilibrium temperature of the mixture. (Take the specific heat of water to be

4.19\,\text{J}\,\text{g}^{-1}\,^{\circ}\text{C}^{-1}