Washing machines clean clothing by forcing a water and detergent
mixture through fabrics. The action of forcing detergent infused water
through your clothing fabric is what enables the detergent to
chemically loosen dirt embedded in the cloth and separate it from the
fabric. Count your blessings; in the old days, people would beat wet
clothes against a rock loosen dirt!
In top loading washing machines the ratchets back and forth dragging
clothing down to the bottom of the washer tub. The clothes then move
back to the top where the agitator grabs them again. In a frontloading washing machine, the clothes tumble through water in the
base of the washer tub over and over again. After the water is pumped
out, the inner drum uses centrifugal force to squeeze water from
fabrics and clothes by spinning between 500 to 1200 RPM
(revolutions per minute.) depending on the washer model.
The process of converting gasoline into motion is called “internal combustion.”
Internal combustion engines use small, controlled explosions to generate the
power needed to move your car all the places it needs to go.
If you create an explosion in a tiny, enclosed space, such as a piston in
an engine, a huge amount of energy is released as expanding gas. A typical
car engine creates such explosions hundreds of times per minute.
The engine harnesses the energy and uses it to propel your car.
The explosions force pistons in the engine to move. When the energy from the
first explosion has almost run out, another explosion occurs. This forces
the pistons to move again. The cycle continues again and again, giving the car
the power needed to run.
Car engines use a four-stroke combustion cycle. The four strokes
are intake, compression, combustion and exhaust. The strokes are repeated over
and over, generating power. Let’s take a closer look at what happens during
each phase of the combustion cycle.
Intake: During the intake cycle, the intake valve opens, and
the piston moves down. This begins the cycle by bringing air and gas into
Compression: As the compression cycle begins, the piston moves up
and pushes the air and gas into a smaller space. A smaller space means a
more powerful explosion.
Combustion: Next, the spark plug creates a spark that ignites and
explodes the gas. The power of the explosion forces the piston back
Exhaust: During the last part of the cycle, the exhaust valve opens to
release waste gas created by the explosion. This gas is moved to
the catalytic converter, where it is cleaned, and then through
the muffler before it exits the vehicle through the tailpipe
In the refrigeration cycle, there are five basic components:
fluid refrigerant; a compressor, which controls the flow of
refrigerant; the condenser coils (on the outside of the fridge);
the evaporator coils (on the inside of the fridge); and
something called an expansion device.
1. The compressor constricts the refrigerant vapor, raising its
pressure, and pushes it into the coils on the outside of the
the hot gas in the coils meets the
cooler air temperature of the kitchen, it
becomes a liquid.
3. Now in liquid form at high pressure,
the refrigerant cools down as it flows into
the coils inside the freezer and the fridge.
4. The refrigerant absorbs the heat inside
the fridge, cooling down the air.
5. Last, the refrigerant evaporates to a
gas, then flows back to the compressor,
where the cycle starts all over.
Electric fans are
comprised of a motor run
by electric current, which
is attached to fan blades
via a shaft. This rotor
shaft is run by the motor,
and turns the fan blades
at different speeds
depending on the speed
set for the motor.
The number of blades and the general revolutions per minute of the
motor can vary greatly depending on the model of the electric fan.
While all fans, hand operated and electric, move the air that is in a room
or space, only electric fans are actually efficient at cooling people down.
This is because the energy expended to wave a manual fan creates heat
in the body, and the fan's air does not do enough to counteract it.
Additionally, the velocity of an electric fan changes the air pressure and
lowers the temperature.
Speakers come in all shapes and sizes, enabling you to listen to music on
your iPod, enjoy a film at the cinema or hear a friend’s voice over the
In order to translate an electrical signal into an audible sound, speakers
contain an electromagnet: a metal coil which creates a magnetic field
when an electric current flows through it. This coil behaves much like a
normal (permanent) magnet, with one particularly handy property:
reversing the direction of the current in the coil flips the poles of the
Inside a speaker, an electromagnet is placed in front of a
permanent magnet. The permanent magnet is fixed firmly into
position whereas the electromagnet is mobile. As pulses of
electricity pass through the coil of the electromagnet, the direction
of its magnetic field is rapidly changed. This means that it is in
turn attracted to and repelled from the permanent magnet,
vibrating back and forth.
The electromagnet is attached to a cone made of a flexible material
such as paper or plastic which amplifies these vibrations, pumping
sound waves into the surrounding air and towards your ears