Fig. 3.1 shows a metal coffee cup on a metal warming plate. [Figure 3.1, Figure 3.2] There is a small electrical heater inside the warming plate that keeps the plate hotter than the coffee.

1. (a)Describe how heat is transferred through the metal and then to all of the liquid in the cup.[3]
2. (b)A cup of a different shape is placed on the same heater, as shown in Fig. 3.2. The two cups are made of the same metal and contain the same amount of coffee. Explain why the coffee in the cup in Fig. 3.2 is not kept as warm as the coffee in the cup in Fig. 3.1.[1]
3. (c)(i)The outside surface of the cup can be either black or white and can be either dull or shiny. Underline which colour and which type of surface is best to keep the coffee warm. black white dull shiny[1]
4. (c)(ii)Explain your answer to (c)(i).[1]

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