Download Understanding Electricity Part II Las Vegas

Understanding Electricity:
Part I
What is the source of the electric field
Electricity current is constantly flowing into the earth from thunderstorms and
flowing out where there are no thunderstorms. This is the source of the electric
field and the voltage difference is 200 – 300 volts between your head and toes
Benjamin Franklin came up with the terms positive and negative charges. (he
didn’t discover those charges)
Lightning: Temp is 50,000 degrees Farenheit, 6x hotter than the surface of the
sun.
For cloud to ground lightning, negative charges accumulate at the bottom of the
cloud. This forces surfaces electrons to be repelled and the ground becomes
INDUCED positive. The bigger the negative charge built up within the cloud the
more the ground is positively charged. The air can’t separate the charges from
each other so they come together in a big flash and equilibrium is restored when
there is a lightning flash.
Current: When electric current flows, electrons are torn from atoms and flow
freely.
Conductors have loosely held electrons while insulators hold their electrons
tightly.
NASA’s experiment of generating electricity using a satellite on a tether
NASA released a satellite tethered to the space station. In the tether they had a
conduction cable. This whole system was moving at orbital speeds (300m/sec)
within earth’s magnetic field. Since basically there was a conductor moving at
such huge speeds in a magnetic field an electric current was being generated for 5
hours. However, there was so much that it arc’ed and burned through the tether
sending the satellite into space (bye-bye 440 million dollars).
Man on a Wire
Man’s suit is made of stainless steel wire. This gives the current a path of least
resistance. Since the man is not grounded the current flows over him, not into
him. It also flows over the helicopter when the metal wand is connected to the
live power line.
metal wand gives controlled pathway from wire to helo.
once path is made the man connects metal clamps to replace the metal wand so
the man frees his hands.
500,000 volts is the voltage difference between wires and helo.
Volts don’t kill – it’s the amps
water pressure is analogous (similar) to voltage
amount of water current is like the electric current
16 quintillion electrons per second goes thru a 1 amp light. The friction of all of
these electrons moving through a tiny filament causes heat which causes the glow
we call light.
It only takes 1 amp to stop the human heart.
Hoover dam (an example of a hydroelectric power plant)
726 feet high: turns energy of falling water into electrical energy
Purpose to electrify rural areas . services a million people.
Power: watts= voltage (volts) x current (amps)
Kilowatt: 1000 watts
4 billion kilowatts for California, Nevada, and Arizona
Arizona wing is over two city blocks long and 9 generators are devoted to
producing 16, 500 volts. Each generator can provide for a city of 100,000 per
turbine.
Electricity at a power plant is made the oppose way that NASA tried to produce it:
Instead of moving a conductor rapidly through a magnetic field, a magnet is
moved rapidly within a huge coil of conducting wire (the wire doesn’t move – the
magnet does).
How is electricity made: falling water spins blades each of the turbine, and in turn
the turbine spins the magnet within a huge coil of wire.
If electric power plant is a coal burning one then coal is used to heat water to
make steam. This steam at high pressured is used to move blades similarly of a
turbine and the rest of the process is the same.
If the power plant is a nuclear one then the water is heated from nuclear fission
reactions, steam is created that moves the turbines etc just like above.
Voltage leaving plant is boosted but it is stepped down to 110 volts for your
homes
DC : Direct current. Dry cells – current does not fluctuate – it just flows out to
when it is part of a complete circuit.
AC : alternating current. Current leaves plant and goes to the load (your home)
and goes back to the power plant at a specific frequency.
Understanding Electricity Part II
Las Vegas : Brightest manmade spot on the planet.
Filament offers some resistance to flow of electrons in a tungsten wire. Energy
turns into heat 45oo degrees. F (in Las Vegas bulbs)
Fluorescent bulbs do not generate heat since there is no filament. When switch is
turned on the electricity excites the gas in the bulb so much that electrons go into
a higher energy level – a plasma is made. This extra energy is given off as light.
Coney Island
Electricity made its grand entrance to the world here by Thomas Edison and his
crew – one of whom was Lewis H.Latimer, an African American scientist, poet and
musician - flute)
Largest amusement park in world when it opened. Famous visitors to the park:
Mark Twain (author of: Huckleberry Finn, Tom Sawyer, he also had great sense of
humor and was sort of the stand-up comedian of the time period)
Charles Dickens (authored - Christmas Carol, Tale of Two Cities, Oliver, Great
Expectations)
Sigmund Freud (Father of Modern Psychology)
Herman Melville (wrote Moby Dick)
Walt Whitman ( “America’s poet”, wrote poems about Lincoln and that time
period)
Electric Motor: turns electricity into motion rather than motion (kinetic energy)
into electricity. Video showed an original roller coaster operated by a motor that
still works. It moves belt around a 15 foot wheel - 600 amps -enough to power 3
homes. This coaster has speeds of 54 mph at bottom and riders experience 4G’s.
Recognizing that Organisms have electrical impulses
1780 - Galvani took frog legs and showed that lightning produced an electric field
which made frog legs move. This field produced a voltage across the frog legs.
Heart beats due to electrical impulses sent through and over the heart triggering
and coordinating movement.
This is where 1st – 3rd hour stopped.
These send echoes to the skin that can be recorded by using electrodes and they
can be recorded using an EKG : Electro cardiogram.
Electricity in body caused by chemical reactions in each cell of the body.
Myocardial fibrillation is when heart goes into a spasm and blood basically can’t
be pumped at all. Heart has to be “Defribrillated” using a Defibrillator.
Ventricular Fibrillation : sudden cardiac death when heart muscle spasms.
Multiple short circuits through the heart.
{FYI: Otis Boykin, an African American engineer and scientist invented the
prototype of the pacemaker. He also worked on circuits for Guided Missiles and
for computers. Ironically, he died of a heart attack}
360 Joules per second is the amount of power (watts) that your heart has. There
is a voltage difference of 360 volts.
This is where 4th hour stopped just before this.
Utah Arm : first Myoelectric Arm – is operated by contracting biceps and triceps
muscles. When the brain sends the signal to the muscles, it is intercepted by the
computer and amplified. The arm has a battery pack. So then the person can
move fingers, wrist.
Solar panels are composed of photovoltaic cells. When sunlight shines on the cells
there is a chemical reaction releasing electrons and that’s how current is made
with solar panels.