Question

question 6 of 10
some thermal mugs have layers of materials to keep drinks hot for as long as possible. which combination of layers would work best for this purpose?
a. inner core of steel, air gap, outer layer of plastic
b. inner core of steel, no air gap, outer layer of plastic
c. inner core of steel, no air gap, outer layer of glass
d. inner core of glass, air gap, outer layer of plastic

Explanation:

Steel is a good conductor to hold heat initially. Air is a poor - conductor (insulator), and plastic is also an insulator. An air gap between the inner and outer layers helps to prevent heat loss by conduction. Glass is a better conductor of heat compared to plastic in this context, and having no air - gap allows more heat to escape.

Answer:

A. Inner core of steel, air gap, outer layer of plastic