4 05
Ice cream is made by cooling a mixture of liquid ingredients until they freeze.
Figure 6 shows a bowl used for making ice cream
The walls of the bowl contain a liquid coolant.
The bowl is cooled to -20 °C before the mixture is put in the bowl.
The bowl causes the mixture to cool down and freeze.
Figure 6
Inner metal surface
Liquid
coolant
-20 °C
Outer
plastic
surface
Mixture
0 5.3 Explain why the different thermal conductivities of metal and plastic are important in
the design of the bowl.
[4 marks)

You are a researcher for a golf club manufacturer. you are given two identical looking cubes of a metal alloy. you are informed that they are made of the exact same material, but one is crystalline, whereas the other is amorphous. it is your job to determine which one is amorphous this one is more stress-resistant and is useful in reinforcing golf clubs. which of the following is the best way to determine which is which? a. determine the density of each cube. the more dense one is the amorphous solid. b. melt both cubes and look for a broader range of melting temperatures. the one that melts over a broader range of temperatures is the amorphous solid. c. determine the density of each cube. the less dense cube is the amorphous solid. d. melt both cubes and measure the range of melting temperatures. the one that melts over a narrower range of temperatures is the amorphous solid.