Energy Transfers (GCSE Physics)


Uploaded by freeeschool on 04.09.2012

Transcript:
GCSE Physics – Energy Transfers
Hello! Welcome to a video about Energy Transfers. We are going to look at the types of energy
that we often talk about for GCSE Science and we are going to look at how those types
of energy can sometimes be transferred from one type to another.
That starts off with I think it is very important that we know the types of energy that we are
referring to and down on the left hand side of here, we got the names of those different
kinds of energy that we refer to. They are Sound, Heat, Electrical, Light, Potential,
Nuclear and Kinetic.
Kinetic is just another word for movement energy. So anything that is moving has movement
energy or kinetic energy.
In terms of Potential energy, this is a type of stored energy and there are three kinds
you should be aware of. The first one is called Elastic potential energy. That’s energy
stored in anything that is springy or stretchy. There is Gravitational potential energy. Gravitational
potential energy is energy that has something that has position above the ground. So if
you are to hold your pen high above the ground, you’re giving a little bit more gravitational
potential energy and that can be released by letting it go. The third kind is Chemical
potential. Chemical potential is another type of stored energy, but it is stored in various
types of chemicals. An example is fuel which has hydrocarbons in it and that and they contain
chemical potential energy which can be released on burning.
But very important that you remember this and one way to remember them possibly is to
take the first letter for each and first two letters for the potential; it’s not a real
word but it makes the word “SHELPoNK” and if you can remember the word “SHELPoNK”,
you can probably relate this back to the types of energy.
If we were to hide or get rid of all these, from this, you can probably work out that
we’ve got Sound, Heat, Electrical, Light, Potential, it is important to remember the
three kinds which are: Elastic, Gravitational and Chemical, Nuclear energy and Kinetic energy;
and Kinetic energy is the same as Movement energy.
How does this apply to actual examples? I’ve kept SHELPoNK down the left hand side here
so that we can refer to it. I’m just going to go through a few common examples where
energy transfers can happen.
The first one is a ball just above the ground and it is being held there for a moment by
somebody. It has a type of energy that we would refer to and that one in this case would
be potential energy, but specifically gravitational potential energy that sometimes is abbreviated
as GPE.
If you are to let it go, the ball would then drop and it would lose some of its gravitational
potential energy as it goes down. That would then be actually transferred into kinetic
energy. So a ball dropping from a height transfers gravitational potential energy into kinetic
energy. If we just stop at the point just where it hits the ground, we are going from
gravitational potential energy to kinetic. When it hits the ground, you get a bit of
sound and a bit of heat transferred, but during its movement, that’s the energy transferred
that happens.
Another kind of energy transfer that is not often talked about – this is supposed to
be a spring, but imagine that if you were to take that spring, compress it down, squash
it all the way in so that is completely compressed, you have stored a particular kind of energy
in that spring. If you remember back, that would be elastic potential and you can release
the energy just by letting it go and that would then open up and you get some movement
energy. This squashed spring which has elastic potential and that would then be converted to kinetic
or movement energy.
So that’s another type of energy transfer. More common ones are things like kettles.
The kind of energy transfer that it carries out is it starts off with electrical and then
you get a lot of heat and you will also probably get a bit of sound as well. So it is not just
one type of energy that might be transferred into.
Something else, we have, this is supposed to be coal burning that contains chemical
energy. So we go from chemical potential to heat and light. Another common example is
that of a lamp. Again, we have electrical and that is transferred into heat and light,
just like the coal example.
Okay, so there’s a few example of energy transfers. You should be aware of how to describe
the energy transfers using the imaginary word “SHELPoNK” might help. Of course, you
can use whichever way you want to use to memorize or remember those, but here are some common
examples of energy transfers that you should be able to do this kind of thing for examples
and even if for examples that you didn’t come across before.
[end of audio – 05:51] GCSE Physics – Energy Transfers
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