The Student and The Barometer

Some time ago I received a call from a colleague. He was about to give a student a zero for his answer to a physics question, while the student claimed a perfect score. The instructor and the student agreed to an impartial arbiter, and I was selected.

I read the examination question: "Show how it is possible to determine the height of a tall building with the aid of a barometer." The student had answered: "Take the barometer to the top of the building, attach a long rope to it, lower it to the street, and then bring it up, measuring the length of the rope. The length of the rope is the height of the building."

The student really had a strong case for full credit since he had really answered the question completely and correctly! On the other hand, if full credit were given, it could well contribute to a high grade in his physics course and certify competence in physics, but the answer did not confirm this.

I suggested that the student have another try. I gave the student six minutes to answer the question with the warning that the answer should show some knowledge of physics. At the end of five minutes, he hadn't written anything. I asked if he wished to give up, but he said he had many answers to this problem; he was just thinking of the best one. I excused myself for interrupting him and asked him to please go on.

In the next minute, he dashed off his answer, which read: "Take the barometer to the top of the building and lean over the edge of the roof. Drop the barometer, timing its fall with a stopwatch. Then, using the formula x=0.5*a*t^2, calculate the height of the building." At this point, I asked my colleague if he would give up. He conceded, and gave the student almost full credit.

While leaving my colleague's office, I recalled that the student had said that he had other answers to the problem, so I asked him what they were. "Well," said the student, "there are many ways of getting the height of a tall building with the aid of a barometer. For example,if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the skyscraper's shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the skyscraper.

"Fine," I said, "and others?"

"Yes," said the student, "there is a very basic measurement method you will like. In this method, you take the barometer and begin to walk up the stairs. As you climb the stairs, you mark off the length of the barometer along the wall. You then count the number of marks, and this will give you the height of the building in barometer units." "A very direct method."

"Of course. If you want a more sophisticated method, you can tie the barometer to the end of a string, swing it as a pendulum, and determine the value of g [gravity] at the street level and at the top of the building. From the difference between the two values of g, the height of the building, in principle, can be calculated."

"On this same tack, you could take the barometer to the top of the building, attach a long rope to it, lower it to just above the street, and then swing it as a pendulum. You could then calculate the height of the building by the period of the precession".

"Finally," he concluded, "there are many other ways of solving the problem. Probably the best," he said, "is to take the barometer to the basement and knock on the superintendent's door. When the superintendent answers, you speak to him as follows: 'Mr. Superintendent, here is a fine barometer. If you will tell me the height of the building, I will give you this barometer."

At this point, I asked the student if he really did not know the conventional answer to this question. He admitted that he did, but said that he was fed up with high school and college instructors trying to teach him how to think.

The name of the student was Niels Bohr, who later received the Nobel prize for Physics.

You Might Be A Redneck If...
You Might Be A Redneck If... ==================================== 
The family business needs a lookout.Three quarters of the clothes you own have logos on them.You cash your checks at the local liquor store.On Sunday's people stop by to ask if you're having a yard sale and you're not.People hear your car a long time before they see it.Your dad walks you to school because you are both in the same grade.Your house doesn't have curtains, but your truck does.More than one living relative is named after a southern civil war general.Your Junior/Senior Prom had daycare.You think that John Deere Green, Ford Blue, and Primer Gray are the three of the primary colors.Your belt buckle weighs more than three pounds.You ever ate roadkill for dinner.Your kids are going hungry tonight because you just had to have those Yosemite Sam mudflaps.Your truck has a new sunroof because the shotgun fell off the rack when you slammed the door.You have spent more on your pickup truck than on your education.You have to go outside to get something out of the 'fridge.Your father encourages you to quit school because Larry has an opening on the lube rack.You call your boss "Buddy", on a regular basis.Birds are attracted to your beard.Your watchband is wider than any book you've ever read.You ever named a child after a dog.You are known for your homemade squash wine.You're a lite beer drinker, because you start drinking when it gets light.You have to go down to the creek to take a bath.You ever took a six pack to a job interview.There are two or more unfilled warrants for your arrest.All the back pockets in your pants have circular holes.You have one or more rolled vehicles (running or not) in your possession.Your lifetime goal is to own a fireworks stand.You dated your daddy's current wife in high school.Your mom gives you tips on how to sneak booze into sporting events.You have started a petition to change the National Anthem to "Georgia on My Mind".You have spray painted your girlfriend's name on an overpass.Your beer can collection is considered a tourist attraction in your home town.If going to the bathroom in the middle of the night involves putting on shoes (if you have them) a jacket and grabbing a flashlight.You buy a case or more of oil a month.A family feud arises Sunday morning between family members who want to watch Jimmy Swaggart and those who want to watch wrestling.Your truck stalled on the highway and you never went back for it.Your car has been towed more than twice as an abandoned vehicle.When Sears eliminated their catalog you were forced to start buying toilet paper.If the fifth grade is referred to as "your senior year,"You wake up with both a black eye and a hickey.You own more cowboy boots than sneakers.You have been fired from a construction job because of your appearance.You think the last words to the Star Spangled Banner are "Gentlemen, start your engines." or "Play Ball..."When you take your trash to the dump and you return home with more stuff than you left with.You roll you hair with soup cans and wash it once a year.You've painted a car with house paint.During your senior year you and your mother had homeroom together.Jack Daniels makes your list of "most admired people".Your home has more miles on it than your car.The first words out of your mouth every time you see friends are "Howdy!" "HEY!" or "How Y'all Doin?" (If they respond with the same... they're a redneck too!)You have a color coordinating rope that ties down your car hood.The most serious loss from the earthquake was your Conway Twitty record collectionYou won't stop at a rest area if you have an empty beer can in the car.People come to your house to ask if they can hunt on your front lawn.It's easier to spray weed killer on your lawn than mow it.You've had to remove a toothpick for wedding pictures.You go to a Tupperware party for a haircut.You sit up all night with a sick dog, but make your wife stay up with a sick kid.The directions to your house include "turn off the paved road".You stand under the mistletoe at Christmas and wait for Granny and cousin Sue-Ellen to walk by.You've been to a funeral and there were more pick-ups than cars.Your grandmother has ever stopped by the side of a highway to take a leak.You've been too drunk to fish.Taking your wife on a cruise means circling the Dairy Queen.You know which leaves make the best substitute for toilet paper.The biggest fashion risk you take is which plaid you'll wear to the 4-H Fair.You think God looks a lot like Hank Williams, Jr., and heaven looks a lot like Daytona Beach, Florida.There have been multiple attempts to repossess your appliances.Your mama can back down a biker.Your bike has a gun rack on it.The tobacco chewers in your family aren't just the men.You have flowers planted in a bathroom appliance in your front yard.Your dog and your wallet are both on chains.You ever made change in the offering plate.You consider pork and beans to be a gourmet food.You own at least 20 baseball hats.You consider a three piece suit to be: a pair of overalls, a plaid flannel shirt and thermal underwear.You ever used a Weed Eater indoors.You can't get married to your sweetheart cause there is a law against it.You use the term `over yonder' more than once a month.There are four or more cars up on blocks in the front yard.Your mother has gotten into a fistfight at a high school sports event.Your brother-in-law is your uncle.Your two year old has more teeth than you do.You think that Dom Perignon is a mafia leader.You kill dinner two or more times a week.You need an estimate from your barber before you get a haircut.You prominently display a gift you bought at Graceland.You have more tattoos than teeth.You ever hit a deer with your car... on purposeDressing up is wearing the flannel shirt without any rips in it.You refer to the duct tape on your car as "chrome".You've ever had to bum chewing tobacco from your wife.You have a rag for a gas cap (on a car that does run).Your richest relative invites you over to his new home to help remove the wheels and install the skirt.When you run out of gas, you put gin in the gas tank.Your front porch collapses and more than six dogs are killed.You have more belt-buckles than pants.The neighbors started a petition over your Christmas lights.Your vehicle has a two-tone paint job: primer red and primer gray.The rear tires on your car are at least twice as wide as the front ones.You know of at least six different ways to bend the bill of a baseball hat.You mow your lawn and find a car.Your classes at school were cancelled because the path to the restroom was flooded.You ever had to turn your pickup truck around because of bridge clearance restrictions.Your idea of dressing up is putting on your other hat.The primary color of your car is "bondo".You just bought an 8-track player to put in your car.Exxon offered you royalties for your hair.You have to check in the bottom of your shoe for change so you can get grandma a new plug of tobacco.You are still holding on to Confederate money because you think the South will rise again.Your `huntin dawg' cost more than the truck you drive him around in.When you leave your house, you are followed by federal agents of the Bureau of Alcohol Tobacco and Firearms, and the only thing you worry about is if you can loose them or not.Your name is Junior, Junior.You have a picture of Johnny Cash, Willie Nelson, or Elvis over your fireplace.You consider your license plate personalized because your dad made it in prison.Fifth grade was the best six years of your life.You call your sister, "Dear."You hit a bump in the road and lose half of your worldly possessions.One or more gears in your car don't work.There is a sheet hanging in your closet and a gun rack hanging in your truck.You have refused to watch the Academy Awards since "Smokey and the Bandit" was snubbed for best picture.You're moved to tears every time you hear Dolly Parton singing "I Will Always Love You".You wish your outhouse were as nice as those at the state park.You have a very special baseball cap, just for formal occasions.Anyone in your family died right after saying "Hey, Y'all watch this!".Your only condiment on the dining room table is the economy size bottle of ketchup.Your yard contains engine parts to more than one vehicle.You consider a six-pack and a bug-zapper high-quality entertainment.You ever drove a truck into the creek just to see if it would float.You think re-booting your machine refers to kicking the truck tires the second time it won't start.The theme song at your high school prom was `Friends in Low Places'There have been two or more failed repossession attempts on your car.You have scars on the back of your hand where Uncle Jeb stabbed you while you were reaching for the last piece of fried chicken.Your hairdo has ever been ruined by a ceiling fan.You can change the oil in your truck without ducking your head.Your wife has a beer belly and you find it attractive.Your father fully executes the "pull my finger" gag during Christmas dinner.Stealing road signs is a family outing.Every socket in your house breaks a fire code.Your dog has fleas on the inside of its ears.Your dog can't watch you eat without gagging.You have two or more sets of bald tires.You participate in the "who can spit tobacco the farthest contest".You wear your ball cap when you eat in a restaurant.You can fart the first six notes of the Star Spangled Banner.Getting a package from your post office requires a full tank of gas in the truck.You owe the taxidermist more than your annual income.Your child's first words are "Attention K-Mart shoppers!".You think the Mountain Men in deliverance were just "Misunderstood".You only have pants with a boot cut.Your wife's best pair of shoes are steel-toed Red Wings.After the prom you drove the truck while your date hit road signs with empty beer bottles.You ever parked a Camero in a tree.On your first date you had to ask your Dad to borrow the keys to the tractor.You have lost at least one tooth opening a beer bottle.Someone asks to see your ID and you show them your belt buckle.You think that beef jerky and Moon Pies are two of the major food groups.Your parakeet knows the phrase "Open up, Police!".Anyone in your family wrestles alligators for a living.You look upon a family reunion as a chance to meet `Ms. Right'You think the stock market is a place to buy hogs.You think taking a bubble bath starts with eating beans for dinner.You have the word "howdy" in your answering machine message.After removing the empty beer cans from your car, you find that it gets fifteen more miles to the gallon.During your wedding, when you kissed the bride, your John Deere hat fell off.You have more than two brothers named Bubba or Junior.You have an Elvis Jell-o mold.Your mother comes outa the bathroom and says "Y'all come look at this before I flush it"You fish in your above-ground pool, especially if you catch something!Yer mom calls ya over to help, cause she has a flat tire...on her house.Your sister's education goal is to get out of high school before she gets pregnant.You think that the Styrofoam cooler is the greatest invention of all time.You ever financed a tattoo.You saved lots of money on your honeymoon by going deer hunting.Someone asks, "where's your bowling bag?" and you answer, "she's at home with the kids."Your favorite Christmas present was a painting on black velvet.You can tell your age by the number of rings in the bathtub.You need one more hole punched in your card to get a freebie at the House of Tattoos.You can talk for more than 20 minutes on the difference between squirrel and rabbit stew.You've been on TV more than five times describing what the tornado sounded like.You bring your dog to work with you.You ever barbecued Spam on the grill.Your gene pool doesn't have a "deep end".You bought a DVR so you could tape wrestling while you are at work.There is a stuffed 'possum anywhere in your house.You celebrate groundhog day 'cause you believe in it.Your girl wears a dress that is strapless and a bra that is not.You have a Hefty bag for a Car/Truck convertible top.Anything outside the lower 48 is "overseas."The UFO hotline limits you to one call a day.You walk your dog and you both use the same tree down on the corner.Thanksgiving dinner was ruined because you ran out of ketchup.In tough situations you ask yourself, "What would Curly do?".You painted racing flames on the John Deere.Your wife has ever had to ask you to move the car's radiator so she could take a bath.You have to honk the horn to get the chickens out of the driveway when you come home.You have to wash your hands before going to the bathroom.You're afraid to wash your car because it may stop running.There are enough empty beer cans in your truck that if you turned them all in, you could buy another six-pack.Your family tree doesn't fork.You think the best beer is brewed in Milwaukee.The blue book value of your truck goes up and down depending on how much gas it has in it.Your mother keeps a spit cup on the ironing board.You have a Hefty bag on the passenger side window of your car.You get mud on your tires when you visit your mom.You consider "Outdoor Life" deep reading.You ever put oil or anti-freeze in your truck in a K-mart parking lot.You can belch and say your name at the same time.The diploma hanging in your den contains the words "Trucking Institute".You ever worn a tube top to a wedding.You grow Vidalia onions, rather than considering them a gourmet item.Fewer than half of your cars run.You think the best way to keep things cold is to leave'em in the shade.You ever climbed a water tower with a bucket of paint to defend your sister's honor.Your idea of a 7 course meal is a bucket of KFC and a sixpack.Someone asks to see your marriage license, and you have to dig through the floorboard of your GTO.You know how many bales of hay your car holds.You consider a good tan to be the back of of your neck and the left arm below the shirt sleeve.You wrote in Richard Petty's name on a presidential ballot.