A water-filled paper cup held in a flame will not catch fire because
A)the inside of the paper is wet.
B)water is an excellent conductor of heat.
C)paper is a good conductor of heat.
D)the paper cup cannot become appreciably hotter than the water it contains.

Question

Quizplus · Accepted Answer

When the paper cup is filled with water, the water absorbs the heat from the flame and keeps the temperature of the paper cup below its ignition point. By being in contact with the water, the paper cup cannot become appreciably hotter than the water it contains, preventing it from catching fire. The fact that the inside of the paper is wet (choice A) and the water is an excellent conductor of heat (choice B) are also supporting reasons for why the cup does not catch fire. However, the most correct answer is D because it provides the main reason for why the cup does not catch fire. Choice C is incorrect because paper is actually a poor conductor of heat, which is why it is used to insulate objects from heat.

A Water-Filled Paper Cup Held in a Flame Will Not