Slinking Science: Take a Slinky Toy for a Walk

Key concepts
Physics
Engineering
Inclined plane
Gravity
Momentum

Introduction
Have you ever watched a Slinky "walk" down a flight of stairs and wondered how it works? It's a fascinating thing to see and a big part of the Slinky's appeal. These spring toys have been popular for well over half a century; your parents, or even grandparents, may have played with them. Slinkies not only make fun toys, they are also great for doing physics and engineering activities. In this activity you will investigate how the angle of an inclined plane affects how well a Slinky can walk down that plane. What angle will enable the Slinky to go for the best walk?

Background
The Slinky is a classic toy in the U.S. and an interesting tool for physics investigations. It was not originally created, however, with either of these purposes in mind. The inventor of the Slinky was a retired Navy engineer named Richard James, who worked in the Philadelphia Naval Shipyard. He initially thought the bouncy springs would be useful on ships for supporting sensitive instruments and keeping them stable during storms at sea. But after the Navy showed no interest in his springs, his wife, Betty, had a better idea?she thought up a catchy name and Slinky the toy was born in 1945.

So how does the Slinky "walk" down a flight of stairs? To do this, the Slinky slowly flips end over end. If you watch closely, you'll see it stretches to reach the next step down, reforms itself, then stretches again to reach the next step, and so on. This process is possible because of gravity and the Slinky's own momentum. In this way a Slinky can walk down other surfaces, too, such as an inclined plane, which is a type of sloping surface that you will use in this activity.

Materials
??? ? A sheet of plywood. Try to find one that's about two feet long by one foot wide, at least.
??? ? Stack of books
??? ? Protractor
??? ? Stopwatch
??? ? Metal Slinky (full size, not a Slinky, Jr.)
??? ? A piece of paper and a pen or pencil
??? ? A helper
??? ? Other sizes and types of Slinkies (optional)

Preparation
??? ? To make your adjustable inclined plane, rest one of the narrow ends of your piece of plywood on a stack of books and the opposite end on the floor.
??? ? Make sure that you have enough books of varying thicknesses to create a 25-degree angle with the inclined plane. This is the largest angle you will be testing. Using a protractor, measure the angle formed where the base of the plane meets the floor.

Procedure
??? ? Adjust the inclined plane so that it is at a 15-degree angle. Use the protractor to confirm the angle formed where the base of the plane meets the floor.
??? ? Have a helper get ready with a stopwatch.
??? ? At the top of the inclined plane hold the Slinky so that it is bent over, making an upside-down U. Let the lower part of the Slinky just barely touch the plane. (This may mean that you are holding around half to two thirds of the Slinky's coils on the upper part of the plane.) Why do you think you should hold the Slinky this way?
??? ? Release the Slinky and have your helper time how long it takes the Slinky to reach the bottom of the plane. Also count how many flips the Slinky does during this time. Tip: Make sure the Slinky doesn't tumble down the plane but actually flips end over end; do not count any of the "walks" in which the Slinky tumbled.
??? ? How long did the Slinky take to reach the bottom at this angle, and how many flips did it make? Write down your results.
??? ? Repeat this at least four more times, each time releasing the Slinky from the same spot at the top of the inclined plane, timing it and counting its flips. How long did it take in these other trials, and how many flips did it make? Write down your results.
??? ? Adjust the inclined plane so that it is at a 20-degree angle. Use the protractor to confirm this.
??? ? Repeat the experiment five times at the 20-degree angle, each time releasing the Slinky from the same spot, timing it and counting its flips. At a 20-degree angle, how long did it take the Slinky to go down the plane, and how many flips did it make? Write down your results for each of the five walks.
??? ? Adjust the inclined plane so that it is at a 25-degree angle, using the protractor.
??? ? Repeat the experiment five times at the 25-degree angle, each time releasing the Slinky from the same spot, timing it and counting its flips. At a 25-degree angle, how long did it take the Slinky to go down the plane, and how many flips did it make? Write down your results for each of the five tries.
??? ? At which angle did the Slinky make the greatest number of flips on its walk? At which angle did the Slinky take the fastest walk?
??? ? Extra: In this activity you investigated how a Slinky walks down inclined planes at 15-, 20- or 25-degree angles, but you can change your inclined plane to create a much smaller or greater slope than these and investigate how well the Slinky walks at the more extreme angles. What are the smallest and largest angles that the inclined plane can be for a Slinky to still be able to "walk" down it?
??? ? Extra: A small Slinky, like a Slinky, Jr., might walk down an inclined plane differently than a larger version. Similarly, a plastic Slinky might travel differently than a metal one of the same size. Pick the angle that worked best in this activity and separately try two different types of Slinkies, either different sizes made of the same material or the same size but made out of different materials. How do the different Slinkies walk down the plane? Does one make more flips or travel faster than the other at the same angle? Why do you think this is?
??? ? Extra: There are many ways to use a Slinky to explore different scientific concepts. One activity to try is to put the two ends on the floor and jump. Can you use the Slinky as a wave detector this way? Alternatively, try wiggling the Slinky back and forth. What can you learn about compression waves by doing this? You can even bang on the Slinky to generate sound. Can you make different pitches? Slinkies have also been used as giant antennas. Can you think of a way to explore using a Slinky as an antenna? What other scientific Slinky uses or investigations can you think of doing?

Source: http://rss.sciam.com/click.phdo?i=17b39bcec532950e14f17d9194cfc575

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Homemade winter cards for friends and family - Pregnancy.org

by Julie Snyder

Postage continues to rise as does the price of greeting cards at the store.

Still, there's something special about receiving holiday greetings in the mail.

There's something even more special when those holiday greetings are homemade, handmade with love.

Relatives and friends will love to receive winter cards made by you and your little one. They are a thousand times better than any store bought cards and can be kept for years to come.

Whether you'll be creating and sending holiday cards or helping your child create memorable keepsakes, these tips will get you started and put smiles on faces -- both those making and those opening the winter cards.

Gather the materials

To make the cards below, we filled our kitchen table with anything we could find around the house that might be useful. The kids thoroughly enjoyed themselves, but it took me a while to come up with anything good. In case you're like me, and it takes some time for your brain to make sense of all the odds and ends, here are a few tips I learned from our two-day card fest.

A few days before you plan to make cards, start filling a box with materials. Throw in anything that might be useful like paper scraps, fabric scraps, envelopes, calendars, and magazines. Anything goes. Let your creativity fill that box!

The card itself

The card's base can be made of:

? Used file folders
? Thin boxes
? Paper grocery sacks
? Card stock
? Recycled computer paper

Decorations

Your home contains nearly endless possibilities to embellish a card, like:

? Scraps of fabric, paper, ribbon
? Magazines, newspapers, old cards
? Parchment paper, corn husks, nature items
? Paint, markers, stickers
? Cotton balls and pads
? Glue and tape

Put it together

Once you've covered your work area and gathered your card-making crew, the fun begins. Your card can be a hand-drawn picture with a few decorations glued on or the crew could try out other techniques.

For a tot, cut out and glue down bold shapes. Add your child?s own embellishments for a great-looking combination.

An older child might enjoy creating 3-D "sticker." Cut a strip from a box and glue it between the card and the cutout. Tada! You've got depth!

If you or the kids need inspiration, one of these ideas may get creative falling faster than snow in a blizzard.

Ideas for all ages

Snowman: Cut two or three circles of felt or use fingernail polish removal pads. Glue them to the card's front. Add faces, arms and sparkles.

Shapes and stickers: Start with a simple shape such as a triangle tree. You child can add ornaments, a star sticker and glitter. All that's left is a holiday greeting.

Stained-glass window: Place a piece of clear contact paper sticky side up. Use yarn to make a design, either free hand or "tracing" a pattern underneath the contact paper. Color the pattern in with glitter and sandwich the design with another piece of contact paper. Glue to your card.

Candles: Cut rectangles for the calendars from scrapbooking or construction paper. Cut flame shapes from yellow or orange paper. Glue into place and add a bright message.

Snow globe card: Fold the card stock and cut into a circle, leaving the top connected. Draw a snowy scene or a winter memory on the front with markers. Paint the dried drawing with a thin coating of glue glitter mix "snow." Glue a few sequins glued on top of the scene. Allow to dry and cover with clear plastic wrap. Write your message inside.

Kid-made holiday cards won't be perfect and shouldn't be! The very fact that they're handmade makes them special. Have you gotten a card that you treasure from a child?

Photo courtesy of iStockphoto.

Source: http://www.pregnancy.org/article/homemade-winter-cards-for-friends-and-family

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Letterman, Hoffman, Zeppelin honored by Obama

WASHINGTON (AP) ? David Letterman's "stupid human tricks" and Top 10 lists vaulted into the ranks of cultural acclaim Sunday night as the late-night comedian received this year's Kennedy Center Honors with rock band Led Zeppelin, an actor, a ballerina and a bluesman.

Stars from New York, Hollywood and the music world joined President Barack Obama at the White House on Sunday night to salute the honorees, whose ranks also include actor Dustin Hoffman, Chicago bluesman Buddy Guy and ballerina Natalia Makarova.

The honors are the nation's highest award for those who influenced American culture through the arts. The recipients were later saluted by fellow performers at the Kennedy Center Opera House in a show to be broadcast Dec. 26 on CBS.

Obama drew laughs from his guests when he described the honorees as "some extraordinary people who have no business being on the same stage together."

Noting that Guy made his first guitar strings using the wire from a window screen, he quipped, "That worked until his parents started wondering how all the mosquitoes were getting in."

The president thanked the members of Led Zeppelin for behaving themselves at the White House given their history of "hotel rooms trashed and mayhem all around."

Obama noted Letterman's humble beginnings as an Indianapolis weatherman who once reported the city was being pelted by hail 'the size of canned hams.'"

"It's one of the highlights of his career," he said.

All kidding aside, Obama described all of the honorees as artists who "inspired us to see things in a new way, to hear things differently, to discover something within us or to appreciate how much beauty there is in the world."

"It's that unique power that makes the arts so important," he added.

Later on the red carpet, Letterman said he was thrilled by the recognition and to visit Obama at the White House.

"It supersedes everything, honestly," he said. "I haven't won that many awards."

During the show, comedian Tina Fey said she grew up watching her mom laugh at Letterman as he brought on "an endless parade of weirdos."

"Who was this Dave Letterman guy?" Fey said. "Was he a brilliant, subtle passive-aggressive parody of a talk show host? Or just some Midwestern goon who was a little bit off? Time has proven that there's just really no way of knowing."

Alec Baldwin offered a Top 10 reasons Letterman was winning the award, including the fact that he didn't leave late night for a six-month stint in primetime ? a not-so-subtle dig at rival Jay Leno.

Jimmy Kimmel, who will soon compete head-to-head with Letterman on ABC, said he fell in love with Letterman early in life and even had a "Late Night" cake on his 16th birthday.

"To me it wasn't just a TV show," Kimmel said. "It was the reason I would fail to make love to a live woman for many, many years."

For Buddy Guy, singers Bonnie Raitt, Tracy Chapman and others got most of the crowd on its feet singing Guy's signature "Sweet Home Chicago."

Morgan Freeman hailed Guy as a pioneer who helped bridge soul and rock and roll.

"When you hear the blues, you really don't think of it as black or white or yellow or purple or blue," Freeman said. "Buddy Guy, your blue brought us together."

Robert De Niro saluted Hoffman, saying he had changed acting, never took any shortcuts and was brave enough to be a perfectionist.

"Before Dustin burst on the scene, it was pretty much OK for movie stars to show up, read their lines and, if the director insisted, act a little," De Niro said. "But then Dustin came along ? and he just had to get everything right."

By the end of the night, the Foo Fighters, Kid Rock and Lenny Kravitz got the crowd moving to some of Zeppelin's hits at the Kennedy Center.

Jack Black declared Zeppelin the "greatest rock and roll band of all time."

"That's right. Better than the Beatles. Better than the Stones. Even better than Tenacious D," he said. "And that's not opinion ? that's fact."

For the finale, Heart's Ann Wilson and Nancy Wilson sang "Stairway to Heaven," accompanied by a full choir and Jason Bonham, son of the late Zeppelin drummer John Bonham.

Zeppelin front man Robert Plant and his bandmates John Paul Jones and Jimmy Page seemed moved by the show.

Meryl Streep first introduced the honorees Saturday as they received the award medallions during a formal dinner at the U.S. State Department hosted by Secretary of State Hillary Rodham Clinton.

Clinton said ballerina Makarova "risked everything to have the freedom to dance the way she wanted to dance" when she defected from the Soviet Union in 1970.

Makarova made her debut with the American Ballet Theatre and later was the first exiled artist to return to the Soviet Union before its fall to dance with the Kirov Ballet.

Clinton also took special note of Letterman, saying he must be wondering what he's doing in a crowd of talented artists and musicians.

"Dave and I have a history," she said. "I have been a guest on his show several times, and if you include references to my pant suits, I'm on at least once a week."

___

Follow Brett Zongker on Twitter at https://twitter.com/DCArtBeat

Source: http://news.yahoo.com/letterman-hoffman-zeppelin-honored-obama-004142953.html

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McAfee says he's left Belize, is still on run

MEXICO CITY (AP) ? Software company founder John McAfee said Monday he has fled from Belize using a bizarre ruse, adding yet another chapter in what threatens to become one of the biggest media fugitive frenzies since O.J. Simpson led police on a low-speed chase in 1994.

McAfee claimed in a blog posting he had evaded authorities by staging an elaborate distraction in neighboring Mexico.

In an email to The Associated Press, McAfee confirmed a posting to his website in which he described, in what appeared to be joking tones, how he mounted the ruse.

"My 'double,' carrying on (sic) a North Korean passport under my name, was detained in Mexico for pre-planned misbehavior," McAfee wrote in the posting, "but due to indifference on the part of authorities (he) was evicted from the jail and was unable to serve his intended purpose in our exit plan."

It was a turn typical of the bizarre saga of the eccentric anti-virus company founder wanted for questioning in connection with the killing of fellow American ex-pat Gregory Viant Faull, who was shot to death at the Belize island where they both had homes in early November.

Since then, McAfee has refused to turn himself in for questioning saying he fears Belizean police would kill him, and has titillated the media with phone calls, emails and blog posts detailing his life on the lam. It has all resulted in a rather undignified media scrum to get interviews with McAfee, complete with taunts.

Vice magazine, two of whose journalists are reportedly traveling with McAfee, posted a story on its website entitled "We Are with John McAfee Right Now, Suckers," along with a photos showing McAfee and VICE editor-in-chief Rocco Castoro.

Wired magazine later said on its website that location information embedded in the photo shows McAfee and the journalists were at Guatemala's Rio Dulce National Park, near the border with Belize, when the photo was taken.

A representative of the Faull family said Monday that the real issues ? the murder of an American who by all accounts was well-liked by his neighbors on Belize's Ambergris Caye ? are getting lost.

"The real issues are that a human life was violently taken, (and) authorities lack all the information ... we're beyond the danger of them being lost, it's become entertainment. This is tragic to the family," said Dan Keeney of Texas-based DPK Public Relations, who has issued statements on behalf of the Faull family.

A woman who answered the phone at an Orlando, Florida phone number listed for Vickie Faull confirmed she was a relative and said that Keeney spoke on behalf of the family, but had no further comment.

"Mr. McAfee is astute at media manipulation, and he's using those skills to great effect," said Keeney. "I would just caution the media not to let themselves be manipulated."

Keeney added in email that "we strongly urge journalists covering the McAfee story not to glorify the words and actions of this person who, by refusing to cooperate and tell police all he knows about the murder of Greg Faull, is harming the investigation of the murder."

"The family of Mr. Faull is concerned that journalists may be assisting Mr. McAfee either implicitly by helping him to create an elaborate fiction that undermines trust in authorities or explicitly in his efforts to escape."

Police in Belize have called McAfee a "person of interest" in the slaying of Faull and asked him to turn himself in for questioning. He has not been charged, however, and thus can travel at will.

Faull was shot to death in his home, a couple of houses down from the compound where McAfee kept several noisy dogs, armed guards and entertained a steady stream of young women brought in from the mainland. McAfee acknowledges that his dogs were bothersome and that Faull had complained about them, but denied killing Faull. Several of the dogs were poisoned shortly before Faull's killing.

For two weeks, McAfee refused to turn himself in and claimed to be hiding in plain sight, wearing disguises and watching as police raided his house. It was unclear, however, how much of what McAfee ? a confessed practical joker ? said and wrote was true.

McAfee did not describe the entire plan, nor did he say where exactly he was now. He noted only that "we are not in Belize, but not quite out of the woods yet."

In a previous interview with the AP, McAfee had said he had no plans to leave Belize.

"I'm not going to leave this country," he had told the AP. "I love this country, this is my home. I intend to fight the injustice that's here from here, I can't do much from outside, can I?"

In Monday's post, McAfee said he left Belize because he thought "Sam," the young Belizean woman who has accompanied him since he went on the lam, was in danger.

"I left Belize because of a series of events which led both Sam and I to believe that she was in danger of capture. She has been my go-between and my eyes and ears in the outside world. I decided to make the move. I will be returning to Belize after I have place (sic) Sam in a safe position. My fight is in Belize, and I can do little in exile."

Police sources in Belize said early Monday they believed he was still in the country. The sparsely populated border between the two countries is unguarded and unmarked in many places.

Rumors arose over the weekend that McAfee had been caught, but Belizean police quickly denied that.

Belize's prime minister, Dean Barrow, has expressed doubts about McAfee's mental state: "I don't want to be unkind to the gentleman, but I believe he is extremely paranoid, even bonkers."

McAfee, who is extremely polite and coherent in telephone conversations, brushes off such accusations, telling the AP "if people want to call that paranoia, they can do so if you wish, that will not concern me."

McAfee, the creator of the McAfee antivirus program, has led an eccentric life since he sold his stake in the anti-virus software company that is named after him in the early 1990s and moved to Belize about three years ago to lower his taxes.

He told The New York Times in 2009 that he had lost all but $4 million of his $100 million fortune in the U.S. financial crisis. However, a story on the Gizmodo website quoted him as calling that claim "not very accurate at all." He has dabbled in yoga, ultra-light aircraft and producing herbal medications.

McAfee has never said where he's hiding. But in his blog, he has claimed to have disguised himself as a grungy street peddler and a foul-mouthed German tourist.

Source: http://news.yahoo.com/mcafee-says-hes-left-belize-still-run-174818954.html

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Video: Grover: Tax fight?s not over

A Second Take on Meeting the Press: From an up-close look at Rachel Maddow's sneakers to an in-depth look at Jon Krakauer's latest book ? it's all fair game in our "Meet the Press: Take Two" web extra. Log on Sundays to see David Gregory's post-show conversations with leading newsmakers, authors and roundtable guests. Videos are available on-demand by 12 p.m. ET on Sundays.

Source: http://www.msnbc.msn.com/id/3032608/vp/50046778#50046778

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Glance: Implementation of health law by state

So you know the people who dashed your hopes of winning that stupidly large Powerball jackpot, instantly crushing your dreams of living like a king and dipping your butt in gold? Everyone who knows them says the first winners are pretty awesome people, and we now know that least one of their mothers is almost absurdly adorable. Granted, we'd be saying pretty glowing stuff, too, if we were neighbors of Cindy and Mark Hill ??who possess one of the two winning $558 million Powerball tickets?? because, hey, it doesn't hurt to be nice to multimillionaires. ...

Source: http://news.yahoo.com/glance-implementation-health-law-state-125406915.html

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Video: New baby elephant born at Oregon zoo

>>> the oregon zoo is already up and walking on her own. check this out. a 300-pound female elephant was born friday morning. that's the baby, by the way. it will be a while before she's ready for visitors. for now, the zoo will monitor the mother and baby very closely and start compiling a list of possible names for the newborn elephant . among the names, among the contenders, baby elephant , little elephant , elephant junior, small elephant , elephant who slightly resembles her mother and elephant who slightly resembled her father that.

Source: http://video.today.msnbc.msn.com/today/50037543/

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