All of the information in this review is what
you will need to know to get a 3 on the end
of quarter assessment tomorrow.
Take notes if you want.
If you know you do not need to retake a
particular section, you need to be
respectful and quiet so others can get the
information.
Electricity
• Electricity is based on the interaction of charged
particles (electrons are negative, protons are
positive).
• Opposite charges attract (pull toward each other).
• Like charges repel (push away from each other).
• Electric force is the ability to attract or repel.
• Electric field is the area around a charged object in
which the force can be felt.
• Forces and fields can increase with more charge.
• Forces are stronger if the objects are closer.
Electricity continued
• Static does not need contact to discharge.
• Current does need contact to complete a circuit.
• Insulators do not allow electricity to flow – rubber,
plastic.
• Conductors do allow electricity to flow – metal, salt
water.
• Electricity can cause electrons to line up and make a
ferromagnetic object become magnetic.
• Electromagnets can be turned off and on (current), and
need contact. The amount of current, the materials,
and the distances between objects can effect the
strength of an electromagnet.
Magnetism
• Ferromagnetic materials (iron, cobalt, nickel) can
be magnetized, and are attracted to magnets.
• Electrons need to ‘spin’ in the same direction and
linen up to create mini magnetic fields.
• Magnets are attracted to or repel other magnets.
• Opposite poles attract (North to South), like poles
repel (North to North or South to South).
Magnetism continued
• Magnets attract ferromagnetic materials.
• Magnets do not interact with other materials.
• Magnetic force is the ability to attract (pull) or
repel (push).
• Magnetic field is the area around a magnet in
which the force can be felt.
• Forces and fields increase with stronger magnets.
• There is a stronger force if the objects are closer.
• Magnets do not need contact in order to attract or
repel.
Energy Transfers/Transformations
• There are 2 main categories of energy: potential
(stored) and kinetic (motion).
• There are 9 subcategories of energy: nuclear,
chemical, elastic, gravitational (all potential);
sound, electromagnetic (all kinetic); and thermal,
electrical, mechanical (both potential and kinetic).
• Objects contain many forms of energy at one time.
• A transfer is the movement of the same type of
energy from one object to another.
Energy Trans continued
• A transformation is the changing of energy from
one type to another within or between objects.
• There has to be a direct connection or cause-effect
relationship for a transfer or transformation to
occur.
• Any change in an object’s motion or position
means that energy has been transferred to or from
the object.
• You usually cannot end a transformation with a
type of potential energy.
• You can use boxes and arrows to show a
transfer/transformation.
Law of Conservation of Energy
• The Law of Conservation of Energy states that
energy cannot be created or destroyed.
• Energy can be transferred or transformed many
times.
• Almost all the energy on Earth is somehow
connected back to the Sun.
• All matter has potential energy based on the fact
that it is made of molecules, and the molecules are
in motion and are made of different chemicals.
Light
• Light moves in an electromagnetic wave – which means
it does not need matter in order to transfer energy.
• Light is much faster than sound.
• Light waves have the main properties of amplitude and
frequency.
• The observable phenomenon related to amplitude is
brightness (lots of waves added together); to frequency
is color (red is low, purple is high).
• White light is made of all the colors of the rainbow.
• In order to see any object, light reflects off of it; the
colors we see are being reflected, while the other
colors are being absorbed by the object.
Light continued
• Light can be absorbed by opaque objects with darker
colors (which transforms into heat), or by softer
objects.
• When light is absorbed, the amplitude decreases and the
frequency stays the same (unless it is white light absorbed by
a colored object).
• Light can be reflected by opaque objects (the lighter
the color, the more is reflected), and smooth surfaces.
• When light is reflected, the amplitude and frequency stay the
same (unless it is white light reflecting off of a colored
object).
• Light can be transmitted by transparent or translucent
objects.
• When light is transmitted, the amplitude and frequency stay
the same (unless it is white light going through a colored
filter), but the light might change speed (refraction).
Sound
• Sound moves as a mechanical / matter wave –
which means that is needs matter in order to
transfer energy. The molecules pass vibrations.
• Sound is much slower than light. It travels fastest
through solids because the molecules are touching,
and slowest through gases because the molecules
are far apart.
• Sound waves have the main properties of
amplitude and frequency.
• The observable phenomenon related to amplitude
is volume (more energy is louder); to frequency is
pitch (high frequency is a high pitched noise).
Sound continued
• Sound can be absorbed by soft objects.
• When sound is absorbed, the amplitude decreases and
the frequency can change depending on the object.
• Sound can be reflected by hard, smooth surfaces.
• When sound is reflected, the amplitude and frequency
stay the same (unless the wave is reflecting off of
multiple surfaces to amplify the sound).
• Sound can be transmitted by any type of matter
that started the vibrations.
• When sound is transmitted, the amplitude and
frequency stay the same (unless the sound is going
through a different material than it started in).
Engineering Design
• Engineering design starts by defining a problem.
• Engineers have to determine criteria (things that need
to happen to make the solution relevant) and
constraints (limitations).
• Engineers then have to design solutions that meet the
criteria and fall within the constraints.
• They then test their solutions, modify them, and test
them again.
• Any modifications along the way are called
optimizations.
• While optimizing, engineers pay attention to the causeeffect relationship of their modifications. They record
each thing that they change, and the specific outcomes
related to each change.