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Friction for Children: 4 Tricks to Help Children Understand Friction

If you’re looking for ways to aid in teaching friction for children then keep reading. So your child comes home from school with questions about friction.  How can you help your child understand this concept?  Without friction life as we know it would not exist.  Every surface would be more slippery than ice.  You could not walk, run, write, or even feed yourself without friction.  Friction for children is as easy as using common examples to guide your explanation.

Friction for children starts with the basics. Friction is a push, pull, or a force which works against the motion of objects that are in contact as they move past each other.  When objects are touching their surfaces tend to stick together, like the tiny loops and hooks of Velcro.  Heat and sound are also produced by friction.  If you rub the palms of your hands together quickly your hands get warm and you can hear the sound that friction creates.

There are three types of friction; sliding friction, rolling friction, and fluid friction.  Sliding friction is caused by two objects touching each other that slide past one another.  For example, when you push a large wooden crate across a floor you push against sliding friction.  The entire surface of the crate that is in contact with the floor slides against the floor, slowing down the motion of the crate.  Rolling friction uses wheels.  If you move the identical large wooden crate with a wagon then you exert a force against rolling friction.  Only the bottom of each wheel is in contact with the floor. Rolling friction is less than sliding friction; it takes less effort to push the crate on the wagon than to push the crate that is directly resting on the floor.  When an object is in contact with a fluid, a liquid or a gas this is considered fluid friction.  Airplanes and race cars are streamlined to reduce fluid friction.  They have smooth, curved surfaces to reduce the friction, called drag, with the air.

When teaching friction for children it’s important to stress how friction can be advantageous.  You light a match using friction.  As you strike a match, friction creates enough heat to ignite a chemical compound in the match head that then burns the rest of the match head.  Automobile brakes work because of friction.  As the brake pads rub against the car’s wheels, the car slows down.  Shoes designed for some sports have special soles to use friction to your advantage.  Baseball shoes and football shoes have cleats to increase friction by sticking to cracks in the ground.  A violinist puts rosin on his bow to increase friction between the bow and the violin strings, therefore producing sound.

 However, friction can also be disadvantageous.  If a door hinge squeaks, the noise is caused by friction.  The space shuttle’s nose and wings heat up dramatically as it returns to Earth from orbit.  The ceramic tiles on the shuttle’s nose and wings are designed to dissipate this heat caused by friction. The moving parts of a car’s engine rub against each other and can stick together, causing the engine to seize and to stop working.  Using oil in a car’s engine protects the parts from friction.  Cooked foods tend to stick to pans.  Teflon on non-stick cookware reduces friction between the food and the pan, causing the food to slide.  Competitive swimmers wear specially designed racing suits to reduce the friction between themselves and the water so that they can swim faster.  A bowler wears extremely flat-soled shoes to slide on the lane right before he releases the bowling ball.  Silicone aerosols, oils, grease, graphite (the very soft form of carbon in “lead” pencils), and ball bearings are all used to reduce friction.

By using every day examples, you can teach friction for children and help them better understand this concept.  The three types of friction, sliding, rolling and fluid, can either be beneficial or detrimental to the motion of objects.  Friction between your pen or pencil tip and the paper you write on allows you to write on the paper.  Friction between the ground or the floor and your feet allows you to run or walk along these surfaces.  Friction between your food and a spoon or fork allows you to eat with these utensils.

 

About the Author

I earned my B.S. degree from Penn State in Earth Sciences and my M.S. degree plus teacher's certification from Drexel University. I have 20 years of teaching experience in both public high school and science museum settings. go to http://www.loriesonlinetutoring.com

Baseball Cleats Ignite

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ELECTRIC BIKER

Pedal-Assisted Pleasure...

Stepping outside my island hideout, I hoist the bamboo-stiffened tarp like a gaff-rigged mainsail and cleat it off to the side of the shed. In the soft interior light, the bike's clear plastic fairing throws off reflections with the promise of motorized adventure only two wheels can offer. 

The machine waits, eager and enticing, as I pull on helmet, goggles and gloves and zip my armored jacket to the chin. The charger's pulsing green light says, "Go!" 

Unplugging the BikeE, I wheel it out under last winter's ravaged apple tree, swing my leg over its low-slanting frame, and settle back in the semi-reclining seat with a sigh of coming home. A quick brake check and final adjustment of the handlebar mirror gives me a moment to focus and quiet the adrenaline surging through me like the voltage I'm about to feed my pony. 

Reaching down, I punch the big red button on the heavy duty controller bolted to the side of the bike's box frame. A red glow reflecting on my glove is the only indication that we have ignition. 

I touch the thumb throttle and any doubt disappears in a surge of torque. 

As Honda Chairman Takeo Fukui reminds us, "Even the best internal-combustion engines still waste more than 80% of the energy created by burning gasoline." 

But electric hub motors can deliver full power directly to the wheel. And if that rotating motivator happens to be just 16-inches in diameter and connected to the front of a low-slung bicycle, you'd better be ready to brace for the kind of acceleration that brings big grins to the faces of all those who believe that fast is good. 

And faster is better. 

Shouting, "Power to the people!" I tuck my feet into the Power Grip straps as the bike moves forward under its own power and each pedal rotates into position. Making for the cove's paved two-lane road, I swing out of the gravel driveway that earlier last summer judo-flipped me into a 10-week aching meditation on paying attention. (Nothing broken and not a scratch on the bike - and no bruises if I'd been wearing the padded mountain bike jacket I always wear now.) Downshifting the internal rear hub transmission, I keep peddling in laid-back comfort for the long climb out of the "gravity well" leading up the relentlessly steep and scenic hill from Ford Cove. 

Passing Olson's farm, the grade inclines. Tilting back in the seat like a light plane pilot on a long climb-out, I keep peddling easily while gradually coming in with full power. Despite the drastically steepening grade, speed continues to hover around 22 kph as the numbers denoting amperage draw tick over quickly on the Cycle Analyst meter: 8, 10, 14, 20… 29 amps! 

Don't try this on a hot summer day without at least a 36-volt motor/battery combo, heavy-duty fuse clip and overbuilt power controller! 

But this classic, power-assisted BikeE handles the load without strain. Even at full power, the whine of the motor is much quieter than the bird cries and soft wash of distant surf. Lulled by the hum of the bike's spinning tires, I lay back in my lawn chair and admire the ocean view as the hill that used to necessitate three panting stops to recharge my "preemie" lungs tops out in trees, sunshine and smiles. 

Starting down the backside, I firm my grip on the handlebars as the bike tips straight down in one long burn of all this "heightened" energy. Weighing over 225 pounds with rider, battery, controller and motor onboard, the BikeE sucks up gravity like rocket juice, accelerating like a Saturn IV leaving the pad. 

In seconds, the speedo whisks past 40 k. 

Whack! A bug bounces off my newly acquired ski-goggles. Good purchase!

Even with power all the way off, at 45 kilometers-per-hour, "organic" regen kicks in as the spinning front hub motor maxes out and begins pumping juice back into the battery. Our descending rush does not slow as 13 amps momentarily surge back into the 36-volt sausage of wired-together Nickel-Metal Hydride laptop batteries cinched to the bike's boxbeam frame in front of the seat. 

Nearly supersonic, I "think" the bike's little front wheel past a jagged pothole. Even though you can't fly over the handlebars in a recumbent crash, a front tire blow-out at 57 k would not be fun. Which is why that Kenda Qwest high-pressure tire is new, internally protected with slime and a Kevlar puncture barrier - and regularly replaced. 

Speed slackens gradually as the BikeE levels out, but it's still another few moments before peddling again takes effect. Downshifting once, twice, three-times on the seven-speed rear sprocket, I thumb the power back in to keep grunt work off the pedals as the next hill looms. One more swooping roller-coaster is followed by a long pleasant flat stretch that finds me lightly blipping the throttle in a "pulse and glide" technique that extends range while keeping peddling speed near a brisk 30 k. 

Onboard a conventional bike, I'd be staring down at the pavement, back bent, with my weight on my aching wrists. But unlike full recumbents, which put riders almost on their backs, the BikeE's more upright seating gives me good eye contact with the astonished driver of a passing car - as well as fine views of unscrolling woods, sky and farms. I once passed Hogan trotting his horse along this stretch, proving conclusively the "one horsepower-plus" rating of my 480-watt Crystallite e-motor. 

Then comes another long delightful downhill run past a fine sweep of ocean rolling into Little Tribune Bay. Even leveling off, this descent carries me in a rush all the way to the Co-Op bike rack. 

Who says a grocery run has to be boring? 

Or must burn carbon? 

The bike's big wire basket, Spiderman totepack, and extra-long frame allow me to carry more than 30 pounds of cargo with ease. (I've even hauled logs lashed to the frame.) A trailer would turn this bike into a pickup truck, while carrying an extra battery for nearly 100 km range! 

So far, so good. The reliability of this rig is nearly 100% after I learned to obsessively tape, wire-tie and check every looping strand of wire clear of spinning sprockets and pedals. Over less than a year, the 1,800 or so kilometers I've covered on my electrified BikeE translate into roughly 40 gallons of gasoline saved - or more than 800 pounds of CO2 kept out of the atmosphere forever. Except for my own exhalations of course. Which I tend to do anyway. 

Mental and physical health benefits are incalculable. Not to mention the additional personal liberation of saving a fortune on the car I no longer support. At 59 - on my electric bike - life is good! 

No one ever told me the end of the world (as we've known it) would be so much fun.

About the Author

WHO IS WILLIAM THOMAS?

I am an award-winning Canadian author, reporter, photographer and filmmaker. A former Vancouver Sun “photog” – his feature writing and accompanying photographs subsequently appeared in more than 50 publications in eight countries, including translations into French, Dutch and Japanese.

My 30-minute video documentary Eco War won the 1991 US Environmental Film Festival award for “Best Documentary Short”. Excerpts from this “front-lines” chronicle of a three-man environmental emergency response team in Kuwait aired in an eight-part CBC Gulf War mini-series, and have been shown on CNN and NBC television, as well as Noam Chomsky’s feature film, “The Corporation”.

During and immediately after the Gulf War, I served five months in Bahrain, Saudi Arabia and Kuwait as a member of a three-man environmental emergency response team.

Winner of four Canadian feature-writing awards, I am the author of Days Of Deception: Ground Zero and Beyond; All Fall Down: The Politics of Terror and Mass Persuasion, Scorched Earth, Bringing The War Home, Alt Health, Stand Down, Dialing Our Cells: Cell Phone Health Hazards and the recently updated Chemtrails Confirmed.

A former pilot, ocean sailing master and frequent radio talk-show guest, I currently live and work in the Gulf Islands off Canada’s west coast.

Visit my investigative reporting website: willthomasonline.net

Visit my photography website: willthomasphotography.com

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