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>> I'M JOAN CARTAN-HANSEN, WELCOME TO OUR "D4K" WEB-ONLY
SHOA. JOINING ME NOW TO ANSWER YOUR QUESTIONS ABOUT ELECTRICITY
AREJ. PROFESSOR OF MECHANICAL AND BIOMEDICAL ENGINEERING, AND
KIP SIKES, OPERATION ANALYSIS AND DEVELOPMENT MANAGER FOR
IDAHO POWER.
THANK YOU BOTH FOR BEING HERE.
APPRECIATE YOU JOINING US.
>> GLAD TO BE HERE.
>> JOINING NEWS OUR STUDIO A HERE AT IDAHO PUBLIC TELEVISION
ARE THE STUDENTS OF NADINE CHAFFEE'S GATE CLASS FROM
VALLEYVIEW ELEMENTARY.
THANKS FOR BEING HERE.
LET'S GO TO YOUR QUESTIONS.
>> HI, MY NAME IS LEAH AND MY QUESTION IS, WHAT'S THE
DIFFERENCE BETWEEN ALTERNATING AND DIRECT CURRENT?
>> THE DIFFERENCE BETWEEN ALTERNATING CURRENT AND DIRECT
CURRENT, OR D.C., IS DIRECT CURRENT ONLY --
THE ELECTRONS ONLY FLOW IN ONE DIRECTION.
WHEREAS AN ALTERNATING CURRENT THEY FLOW BACK AND FORTH IN
NORTH AMERICA, 60 TIMES PER SECOND THEY CHANGE DIRECTIONS.
>> KATIE WOULD LIKE TO KNOW, HOW IS LIGHTNING ATTRACTIVE TO SHINY
THINGS?
>> LIGHTNING IS ATTRACTED TO ANY OBJECT THAT HAS A DIFFERENT
CHARGE THAN THE CHARGE THAT'S IN THE CLOUDS.
AND IT'S USUALLY SOMETHING THEAS METALLIC.
IT TURNS OUT THINGS THAT ARE SHINY ARE ALSO GENERALLY MADE OF
METAL AND THOSE ARE GOOD CONDUCTORS OF ELECTRICITY.
SO THE LIGHTNING IS GOING TO BE ATTRACT TO SOMETHING THAT'S
METAL AND CLOSE TO THE CLOUD, OR CLOSE TO THE CLOUD THAN ANYWHERE
ELSE.
IT'S NOT JUST SHINY THINGS, BUT THEY'LL ALSO BE ATTRACTED TO THE
TOPS OF TREES OR MAYBE EVEN PEOPLE WHO ARE OUT IN THE MIDDLE
OF A FIELD.
BUT WE MAKE LIGHTNING RODS OUT OF METAL, PUT THEM VERY HIGH SO
THAT'S THE FIRST THING THE LIGHTNING HITS.
AND THEN WE CONNECT THAT LIGHTNING ROD WITH A BIG WIRE
ALL THE WAY DOWN INTO A STAKE THAT'S WAY IN THE GROUND, TO
DISSIPATE THAT ELECTRICITY AND MAKE IT GO AWAY WITHOUT DAMAGING
ANYTHING.
>> MOLLY ASKS, HOW DOES ELECTRICITY TRAVEL THROUGH
WIRES?
>> MOLLY, THE WAY ELECTRICITY TRAVELS THROUGH WIRES IS MUCH
LIKE WATER GOES THROUGH A GARDEN HOSE.
IF YOU'VE EVER EXPERIENCED THAT.
THE ELECTRONS ARE REALLY THE ELECTRICITY THAT'S MOVING
THROUGH THE WIRES AND THEY BUMP AFLONG ATOM TO ATOM IN A
CONDUCTOR.
THE ELECTRONS ARE FREE TO MOVE.
SO THEY PUSH EACH OTHER ALONG JUST LIKE WATER GOES THROUGH A
GARDEN HOSE.
>> JOSIE ASKS, HOW FAR CAN ELECTRICITY TRAVEL?
>> JOSIE, THAT'S A GREAT QUESTION.
IT'S A LITTLE COMPLICATED, BUT GENERALLY SPEAKING IT CAN TRAVEL
VERY LONG DISTANCES.
THE PROBLEM IS, THE FURTHER IT TRAVELS, THE MORE ENERGY WE LOSE
ALONG THE WAY, BECAUSE THE WIRES ARE GETTING A LITTLE BIT HOT.
AND SOME OF THAT ELECTRICITY IS TURNING INTO HEAT.
SO WE TEND TO LIMIT HOW FAR WE MOVE ELECTRICITY, JUST BECAUSE
IT MAKES MORE SENSE, AND WE'LL PUT MORE GENERATORS OR MORE WAYS
TO MAKE ELECTRICITY ALONG THE WAY.
BUT GENERALLY PROBABLY IT CAN TRAVEL SEVERAL HUNDRED MILES,
BUT WE TRY TO KEEP IT SHORTER THAN THAT.
>> SARAH WANTS TO KNOW, HOW DOES A BATTERY STORE ELECTRICITY?
>> THERE ARE A NUMBER OF DIFFERENT TYPES OF BATTERIES.
SO THERE ARE CHEMICAL REACTION BATTERIES IN WHICH THERE'S A
REACTION THAT DIFFERENT ELEMENTS OR --
INTERACT WITH EACH OTHER THROUGH A CHEMICAL REACTION THAT FREE UP
ELECTRONS AND PUSH THEM THROUGH SUCH THAT WHEN YOU THROW THE
SWITCH THEN THE ELECTRONS MOVE.
BUT THERE ARE OTHER TYPES OF BATTERIES, SOME OF THE EARLIEST
ONES WERE JUST DEALING WITH STATIC ELECTRICITY.
SO IF YOU TAKE A GLASS JAR AND LINE IT WITH METAL, YOU CAN
STORE ELECTRONS IN THAT GLASS JAR.
IT'S NOT A VERY GOOD BATTERY.
BUT IT'S ANOTHER WAY TO THINK OF IT.
>> MY NAME IS CHANDLER AND MY QUESTION IS, HOW DO --
HELP MAKE ELECTRICITY?
>> THAT'S A GREAT QUESTION.
LIKE THE PREVIOUS QUESTION ABOUT TIDAL POWER, IT'S ABOUT
EXPERIMENTAL WAYS OF CREATING ELECTRICITY USING RENEWABLE
ENERGY.
SO THERE'S PLANS AND THOUGHTS OF TAKING WIND TURBINES AND FLYING
THEM UP INTO THE HIGHER ALTITUDES WHERE IT DOES MAKE
SENSE TO MAKE THE TOWERS THAT TALL.
BUT THEY PUT THEM ON BIG KITES OR NEXT TO BALLOONS AND ANCHOR
THEM TO THE GROUND WITH CABLES.
AND THE REASON YOU WANT TO DO THAT IS BECAUSE THE WIND IS
ALWAYS STRONGER THE HIGHER UP YOU GO.
AND IF YOU GET VERY, VERY HIGH, MAYBE 100 FEET OR SEVERAL
HUNDRED FEET OR EVEN A THOUSAND FEET, YOU HAVE MUCH BETTER WIND,
MUCH MORE ENERGY TO EXTRACT AND TURN TO ELECTRICITY.
AND IT'S ALSO MORE CONSTANT, WHICH IS ALSO A BIG ISSUE WITH
ALL RENEWABLE ENERGY SOURCES.
>> ADRIAN ASKS, HOW IS LIGHTNING MADE?
>> WELL, YOU CAN'T JUST GO TO THE STORE AND BUY A PACKAGE OF
LIGHTNING.
IT'S REALLY A LOT MORE COMPLICATED THAN THAT, BUT NOT
MUCH.
WHEN CLOUDS MOVE THROUGH THE AIR, IT'S LIKE RUBBING ON
SOMETHING.
SO WHEN THINGS COME IN CONTACT WITH EACH OTHER, ELECTRONS CAN
MOVE FROM ONE TO THE OTHER.
SO AS CLOUDS RUB AGAINST OTHER CLOUDS AND JUST IN GENERAL THE
WINDS IN THE UPPER ATMOSPHERE, ELECTRONS BUILD UP AND YOU GET A
LOT OF ELECTRONS WHICH ARE NEGATIVELY CHARGED, AND OTHER
THINGS ARE POSITIVELY CHARGED.
AND YOU GET -- THE DIFFERENCE BETWEEN THOSE, SO
THEY WANT TO COLLAPSE AND THAT'S THE LIGHTNING BOLT, THE BIG ZAP,
IS TO EQUAL OUT THE POTENTIAL.
SO THERE'S NOT PLUSES AND MINUSES, EVERYTHING WANTS TO BE
HAPPY NEUTRAL.
>> MY NAME IS AUBREY, AND MY QUESTION IS, HOW DO YOU COLLECT
TIELDAL ELECTRICITY?
>> YOU DON'T REALLY COLLECT ELECTRICITY VERY WELL.
ELECTRICITY IS GENERATE AND USED PRETTY MUCH THE SAME TIME.
BUT YOU COLLECT TIDAL ENERGY USUALLY WITH A LAGOON OR SMALL
DAM SO AS THE TIDE COMES IN, MAYBE UP A RIVER, THERE'S AN
AREA NEXT TO THE RIVER WHERE THE WATER CAN FLOW INTO, AND THEN
THEY CLOSE GATES.
THEY CLOSE THE DISPAM AS THE TIDE RECEDES THE LAGOON IS AT A
HIGHER LEVEL ABOVE THE RIVER AND YOU CAN USE THAT DIFFERENCE IN
HEIGHT, THAT DIFFERENCE IN ELEVATION TO DRIVE A TURBINE AND
MAKE ELECTRICITY.
>> I'M SORRY, BUT WE'VE RUN OUT OF TIME.
THANKS TO JOHN AND KIDNA AND KIP FOR ANSWERING QUESTIONS.
AND THANKS TO OUR CLASS FOR PROVIDING US WITH QUESTIONS.
THANKS, GUYS.
[CHEERS] IF YOU WANT TO LEARN MORE ABOUT
ELECTRICITY, CHECK OUT THE ELECTRICITY AREA ON THE "D4K"
WEBSITE.
YOU'LL FIND FACTS, LINKS, GAMES, OUR ELECTRICITY BROADCAST SHOW,
AND LOTS MORE.
AND EVERY WEEK CHECK OUT MY BLOG FOR THE LATEST KIDS' SCIENCE
NEWS.
THANKS FOR JOINING US FOR THIS "D4K" WEB-ONLY.
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