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# ENERGY - Science Year 9

This Prezi will show all the stuff we've learnt for Energy in Science Year 9!! :D
by

## Ji Won Yoon

on 31 July 2011

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#### Transcript of ENERGY - Science Year 9

Science - ENERGY THE LAW OF CONSERVATION OF ENERGY... There are TWO Potential Energy Chemical Potential Energy: The energy is STORED Gravitational
Potential
Energy: The energy is STORED Elastic Potential
Energy The energy STORED Active
Energy. Sound Energy: The energy released Heat
Energy: This energy is often hard to store, Kinetic Energy: This is energy in moving objects. Kinetic energy is changed into other forms of energy when the object/person/(or in this case, pirates) stops moving. (for example, a pirate running away from another pirate.) Energy Transformations Energy
Transfers This is one type of
energy moving from
one object to another. This is one type of energy
converting into one or
more types of energy. one type of energy transformation
is when one pirate falls (kinetic
energy) off a plank, (gravitational
potential energy) and lands this would be KINETIC ---> GPE ---> SOUND this would be KINETIC ---> KINETIC ---> KINETIC ---> KINETIC Efficiency As energy in
an object is
transformed, useful energy released _____________________ energy put in/used up X 100 % Effeciency = (for example, a pirate who is riding on a train (?) calculates that out of every 1000J of energy in the coal used to power the train, only 300J of energy transforms into kinetic energy that makes the train move.) % Efficiency = 300J ____ 1000J X 100 = 30% Efficiency The other 70%
of the energy
is transformed Waves ~~~ To calculate the % of efficiency, this formula is used: There are two
types of waves. Longitudinal - waves that
move from side to side ( <--- see? side2side --->) and Transverse -
waves that move
up and down. (see? up&down ---->) light waves,
and microwaves
(no not the stuff
you heat your
leftover lasagna
in.. -.-) are all TRANSVERSE
WAVES. sound waves are an example
of a LONGITUDINAL WAVE.
They move parallel to the
direction of the motion of the wave. FREQUENCY is the
number of waves in
a given interval. :D WAVELENGTH is the
distance between waves. :D OSCILLATION is the same pattern
in the waves again in time. :D AMPLITUDE is the amount
of energy in a wave. :D The ELECTROMAGNETIC SPECTRUM.
(okay; big, scary word so we can call it EMS for short :D) The electromagnetic spectrum is all the
electromagnetic waves arranged
according to frequency and wavelength. From the (no-dangers-yay) radio waves, to the (large-doses-can-kill-you-ZOMG) gamma waves, there are 7 different waves in the EMS. for more information on the EMS, go to http://snowpod.glogster.com/the-electromagnetic-spectrum There are
both good
uses and
dangers
in the EMS, Heat Energy/Heat Transfer HEAT is a type of energy called HEAT ENERGY. (surprise surprise!) During heat transfer, the heat energy ALWAYS moves in one direction: HOT -------> COLD Some examples of this are.. a pirate touching a hot saucepan and burning himself. a pirate playing outside in snow (YAY SNOW :D) and his body getting colder. Conduction Conduction is the way heat transfers (moves) in solids. Substances that this process happens quickly in are called CONDUCTORS. Solids are usually good conductors, and they let heat pass through easily. Substances that this process happens slowly in are called INSULATORS. Insulators do not allow heat to transfer through easily. Convection Convection is the way that heat transfers in liquids and gases, (or FLUIDS, because they both FLOW~~) by the movement of currents. The heat MOVES with the fluid. This is what
creates a
convection
current, and
its why it
goes up, and
down. Up and
down, again
and again. Radiation Radiation involves no particles, instead the energy is transferred by waves. main types of energy. (or stored energy) in chemicals, or fuels, food or batteries, which is often released in chemical reactions (for example, pirates burning people, digesting people, etc.) some Potential
Energy includes.. and in objects raised from the ground. As
the
object falls, the GPE gets
less, and it falls
faster (for example, a pirate
stepping off the edge
of a plank, and falling
towards the ocean
and his/her death.) in something which can be
stretched or squeezed. (for example, pirates flicking rubber
bands at eachother, and getting red
marks all over themselves.) and some Active Energy includes.. by vibrating solids,
liquids and gases (for example, one
pirate screaming in
another pirate's ear.) because heat moves away
towards cooler places. Heat energy is often released
from other energy changes. (for example, a pirate rubbing his hands to-
gether for warmth because it is snowing. YAY :D) Energy
cannot be
CREATED or
DESTROYED. It can
only be TRANSFERRED or
TRANSFORMED. THE FORM OF ENERGY
DOES NOT CHANGE. pirates stand in a
domino line and
one pirate pushes one type of
energy transfer is when the pirate at the front over,
making the domino effect',
but only on pirates. Energy transfers are 'technically' impossible, because
every energy transfer, one small part of the energy
is transformed into another type of energy. with a splash (sound energy) in
the water below. :D When energy is transformed, some of it usually transformed into heat and/or sound energy. when energy it lets out
different
types of
energy. The more unnessecary types of energy
the object lets out, the less efficient it is. To calculate the % of efficiency, this formula is used: into other types
of energy which are not
useful/wasteful,
such as sound
and heat energy. Waves are
a way that
energy travels. When energy is transformed, it is very rarely
100% efficient during the
transformation. the rest of
the energy is transformed into other types of not useful energy. A wave can be described
as a form of energy that
travels through a medium
from one location to another. (a medium is the substance or
material that CARRIES a wave.) Waves are a way that energy moves
without disturbing particles or matter. for example, pirates
in a stadium (?) The larger the wavelength, the smaller the frequency. The smaller the wavelength, the larger the frequency. watching a game of rugby. they decide to do
a 'stadium wave'. this is not actually all of
the pirates stomping
which would be slightly strange. no, this is like a mexican wave, except in a stadium and the wave goes
from one end of the circular stadium to the other. the pirates stand up in their
seats and sit back down again, not moving anywhere. the energy (mexican/stadium wave) is transferred without the pirates (matter) moving. such as killing cancer
cells (gamma rays), sunbeds and if consumed in
large doses, cancer and
DEATH of cells ): (UV rays) SEEING :D and it can cause blindless (light rays) remote controls and skin burns :O (Infared waves) satellite communication, cooking and internal tissue heating (microwaves) and communication and astronomy with NO DANGERS :D (radio waves) There are three main ways that heat can be transferred: CONDUCTION, CONVECTION and RADIATION. (this will be
explained in more
detail later. :D) The heat moves from the hot object (the saucepan) to the cooler object (the pirate's hand) OUCH! :'O The heat moves from the hot object (the pirates warm body) to the cooler (the cold snow and air). Particles gain heat and vibrate. This vibration transfers the heat from one particle to the next. The vibration and therefore the heat energy travels along the solid. Conduction only happens in SOLIDS. This is because the particles are very close together in solids, and so when they vibrate, the vibration can be transferred along via the particles, and so again transferring the energy. For example, convection is the reason why macaroni rises and falls in a pot of hot water. The warmer parts of the water are less dense and therefore they rise. As the water
rises and goes
towards the
top of the pot,
the water gets cooler,
and it goes towards the bottom of the pot again because it gets denser. For example, a pirate is in space (?) and he shines a really REALLY bright torch towards the earth. The light from the torch is radiated through space without the aid of fluids or solids. It travels by WAVES. This light energy doesn't travel with
our good ol' friends convection
and conduction :D going a little off topic.. to measure the energy in food, we can burn it, and see how much the flame produced from the food product heats up a specific amout of water during a specific amount of time. we can then use this formula to work out how much energy is in that food product. Energy =
(joules) change
in temp
(°C) X specific heat
capacity
(for water;
4200) X mass of
substance
heated
(kg) There are certain colours that absorb (take in) and emmit (let out) thermal radiation. from left to right, the best absorber to the worst absorber is shown:
BLACK --> WHITE --> SILVER thermoses are a good example of how heat is kept in. The inside of the thermos is lined with a silver metal, which is the worst absorber and the worst emmitter, making the hot liquid stay hot for longer than if it was just in a normal cup. THE END :D E-N-E-R-G-Y :D WARNING. PEOPLE SUFFERING FROM SEVERE MOTION SICKNESS SHOULD NOT VIEW THIS PRESENTATION. now, without further ado, lets get going :D the energy is STORED if too many words get in your way of reading, for each click look towards the centre of the screen.
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