The water reservoir inside the plastic container is at room temperature, yet it does not mix with the cold water in the tank below. Explain why.
Suggest why copper is used for the pipe.
Explain, using free electrons, how thermal energy moves through the copper.
As the water close to the copper pipe cools, it begins to mix with the rest of the water in the tank. Explain how this happens.
Calculate the thermal energy removed from $250\,\text{g}$ of water when its temperature falls from $21\,^{\circ}\text{C}$ to $7\,^{\circ}\text{C}$. The specific heat capacity of water is $4200\,\text{J kg}^{-1}\,^{\circ}\text{C}^{-1}$.
Describe the motion of the molecules in a liquid with a uniform temperature throughout.
State what happens to the motion of the molecules in a liquid as the liquid temperature falls.