Why is trapped air a good insulator?

Question

science homework

Really need help dont understand cant find answer anywhere!?!?!? HELP!!

somenathsengupta= how does this answer my question?!??! more details?

Answer 1

Alright, to answer this question, I'm going to have to make sure you know a few things.

1) A substance is a solid, liquid or gas depending on how close or far apart the atoms in the substance are. In solids, the atoms are much more tightly packed.

2) "Heat" is the total amount of kinetic energy on an atomic level.

3) Heat can only transfer when two atoms (or, for that matter, molecules) interact.

Now picture the following scenario:

You enter a very crowded room. You're pushing and shoving like crazy. Because the room is so crowded, even people on the other side of the room are going to have to start moving to compensate for your boorish behavior.

OR

You enter a very nearly empty room. You're still pushing about. But because it's not at all crowded, you only affect the people who are nearby. The people on the other side of the room just stare at you funny.

The people in the room are the molecules of the substance you are trying to transfer heat into. You are the extra kinetic energy, the heat, entering the system. You can only transfer energy into something you're able to come into contact with. In a gas, the heat doesn't have the opportunity to affect the distant molecules.

This is why, when boiling water, the pot gets REALLY hot, the water takes a longer time to get hot, and the air above the water is still cool enough to touch.

Hope this is helpful.

Answer 2

Seeing as though you admit its homework, here you go:

Air is a poor conductor, it transfers heat by convection. If you can stop the air moving it stays warm as it doesn't conduct or radiate heat very well. still air is a good insulator.

This principle is used in many things from clothes, sleeping bags, quilts, house insulation, oven linings, bedding for animals

Answer 3

Think about what is in air, what the definition of an insulator is and what the opposite of an insulator is and hopefully that will lead you to a nice answer which you will get top marks for!!

Answer 4

Same reason a wetsuit keeps you warmer than just swimming trunks - if air (or water) is trapped and stationary next to a warm object, it absorbs the heat itself and creates a warm protective layer between the warm thing and the circulating air/water outside.

Sure there's a better explanation than mine out there though - try www.bbc.co.uk and go to the bitesize revision section.

Answer 5

Because air is a bad conductor of heat.

Answer 6

because it doesn't steal heat like other substances. it's why cold water divers use drysuits to stay warm.