Download File - Physics e

Energy notes
Potential energy - the energy in matter due to_______________________________________________. Various forms
of Potential energy include:
Elastic – A trampoline resists being stretched out of shape
Electrical – A battery operated flashlight converts electrical potential energy into light when turned on
Gravitational – Like an apple falling from a tree
Chemical – Energy in food is used by our bodies to move; in a lighted firecracker it is used to make a loud sound and
scatter pieces of the firecracker
Kinetic energy - energy of _______________________________________
Chemical energy is _______________________________________. Examples: ___________, ________________,
______________, and ______________ are fuels that contain ________________________. When these fuels are
burned, the chemical energy is released as heat.
Electrical energy is ___________________________________________________________________. It can be
generated at a _________________________ or inside a ______________________. Lightning and static electricity are
also forms of ________________________________.
Heat (Thermal) energy is _______________________________________________________________________
_______________________________________________________________. For example, when you heat a pot of
water on a stove, the heat from the burner adds energy to the water, causing the water molecules to move around
more rapidly, increasing the water’s thermal energy.
Nuclear energy is ______________________________________________________________________ An atom's
nucleus can be split apart. When this is done, a tremendous amount of energy is released. The energy is both heat and
light energy. This energy, when let out slowly, can be harnessed to generate electricity. When it is let out all at once, it
can make a tremendous explosion in an atomic bomb.
The word fission means to split apart. Inside the reactor of an atomic power plant, uranium atoms are split apart in a
controlled chain reaction. In a chain reaction, particles released by the splitting of the atom go off and strike other
uranium atoms splitting those. Those particles given off split still other atoms in a chain reaction. In nuclear power
plants, control rods are used to keep the splitting regulated so it doesn't go too fast.
Another form of nuclear energy is called fusion. Fusion means joining smaller nuclei (the plural of nucleus) to make a
larger nucleus. The sun uses nuclear fusion of hydrogen atoms into helium atoms. This gives off heat and light and other
radiation.
Light (Radiant) energy is ________________________________________________________________. Examples of
sources: __________________________________________________
quiz time :-) (continue to watch the ppt show)
Any of the above forms of energy can be changed into other forms of energy. However, no energy is ever lost, nor can it
be created from nothing. This can be stated as a law so that it can be applied to new situations as they are encountered:
Energy is never created or lost, it can only be converted from one form of energy to other forms of energy.
Energy flow diagrams can illustrate how energy is transformed from one form of energy to other forms of energy.
There is often branching where one form of energy can be transformed into two or more other forms at the same time.
The diagram shows a mobile phone in use.
A CD player uses the electrical energy in a battery to produce sound energy. This can be represented by an energy flow
diagram.
YOUR TURN
Sketch energy flow diagrams for the following:
1.
2.
3.
4.
5.
6.
matchstick that has just been struck
portable laptop computer
person running up a staircase
electric knife cutting bread
soccer player shooting a goal
a television set.
You do not have to draw pictures of the devices. Boxes can be used to represent the devices.