It’s that
time of year where all the other girls trade their skirts and summer dresses in
for leggings and those trendy sweaters. Me? Oh well, I just wear jeans and post-punk
band tee shirts all year round. Anyways, the point is, things are getting
cooler as the female populous’ attire shows. I propose that we learn about
something especially relevant this time of year: heat! Specifically how heat
transfers so we learn how we stay toasty. First, before we go more into that,
let’s briefly talk about temperature. Temperature is a measure of the average
value of the motion of molecules. The more energy molecules have, the faster
they move. Heat transfer is the transfer of thermal energy, always from a
warmer object to the cooler object. The cooler object will become warmer and
the warmer object cooler. There are three main ways that thermal energy is
transferred: conduction, radiation, or convection.
Conduction is the form of heat
transfer via direct contact. It occurs mainly in solids and liquids. The atoms and
molecules within the substance only move a short distance before they contact
each other. That’s the reason it happens more in these matter states than in
the gas state; because the atoms and molecules are closer together inside
solids ad liquids. An example would be eating a hot french-fry and burning your
tongue because you couldn’t wait a few minutes for it to cool down. Also
touching a hot metal handle with a bare hand is an example of conduction; and
stupidity. Both of these examples were experienced firsthand.
Radiation is
received by light and heat. It is the only form of energy that travels in
space. This is perhaps the most important form of heat transfer when it comes
to all the ways we use it. We use radiation heating when we warm ourselves by a
fire, and most importantly from the sun.
Convection
is another way to transfer thermal energy. This is the transfer of energy by the
movement of atoms and molecules. Convection occurs mainly between liquids and
gasses because the flow of these two forms is a lot more fluid than solids.
These easily moving particles travel from one place to another while
transporting energy. An example of this would be a pot of water getting heated
on a stove.
Now that we
know the rudiments of thermal energy we can talk about thermal conductors.
Conductors are materials that easily transfer thermal energy. Conductors are
used a lot in cooking for this reason.
That’s why your pots and pans are metal; they’re good conductors. Speaking
of conductors, they sort of have an opposite; insulators. Insulators are
materials in which thermal energy does not flow easily. Materials like fur,
feathers, and plastic foam are all poor conductors, but great insulators. Blankets keep you warm because they are
really good insulators that trap your heat around you so you stay warm,
obviously the same goes for feathers, fur, and clothing with good coverage. If
something is a good conductor, like copper, it will be a weak conductor.
I also want
to talk about how rooms stay warm. It’s in part to the insulation in your home,
but also because heating systems. A heating vent should be placed on the floor
in order to evenly heat a room, because the heat will travel up and down. If
placed near the ceiling it wouldn’t heat the room as well.
Now for some
interesting facts: Things with more molecules have more energy. Between a tiny,
but burning match, and a large, ice sculpture, the sculpture will have more
heat energy despite being frozen because it is larger and has more molecules!
Things will also take up more space if they’re hotter. An interesting fact
about convection is that it helps make the world habitable by keeping our
temperature much cooler than it would otherwise be.
I’m pretty
sure that about coves everything you should learn about heat transfer. Remember
to stay warm this wintery season. Be sure to leave a comment!
links for images:
Types of Heat Transfer
Radiation
Convection
Conduction
Insulators
Conductors
No comments:
Post a Comment