QUES: Force is a vector. What then is a vector? Think about how you would give directions to a friend. You would not say, just walk half a mile. The person may walk a half mile in the wrong direction! More information is needed. You may say, follow this particular road for a half mile. You may say, look for the green house on Sumter St. In both examples, you provided a direction. You also gave the distance. In other words, you provided a vector. You did not just give a distance. Both pieces of information are needed to find a location. This is just like describing forces. To explain forces, both size and direction are needed. Notice the girl in Figure 1.1. She is pushing the swing away from herself. Thats the direction of the force. She can give the swing a strong push or a weak push.
Do you have any questions?
MY QUESTION: How far is the green house on Sumter St.?

QUES: The digestive system is the body system that digests food. It digest food in two ways, mechanically and chemically. Both help in the process of turning food into nutrients. The digestive system also eliminates solid food waste. The major organs of the digestive system include the mouth, esophagus, stomach, and small and large in- testines. These organs all work together to help you gain energy from the food you eat. Digestion starts in the mouth. When food is swallowed, it travels through the esophagus to the stomach. In the stomach, digestion continues and a small amount of absorption of nutrients takes place. Most chemical digestion and nearly all absorption of nutrients take place in the small intestine. This organ consists of three parts: duodenum, jejunum, and ileum. The large intestine is the last stop in the digestive system. This is where water is absorbed. The food not digested is released as waste.
Do you have any questions?
MY QUESTION: What two things does the digestion system do for the body?

QUES: The 1933 double eagle, a $20 gold piece with a mysterious history that involves a president, a king and a Secret Service sting operation, was auctioned Tuesday last night for a record price for a coin, $7.59 million, nearly double the previous record. The anonymous buyer, believed to be an individual collector who lives in the United States, made the winning bid in a fiercely contested nine-minute auction at Sotheby's in Manhattan. Eight bidders were joined by 500 coin collectors and dealers in an auction house audience seemingly devoid of celebrity bidders, while an additional 534 observers followed the bidding on eBay. As auction houses prepare for their fall seasons in an uncertain economy, the sale price "suggests that the marketplace for important items is enormously strong," said David Redden, a vice chairman at Sotheby's, who was the auctioneer. "This is an astonishing new record for a coin," he said. In an unprecedented move, the auction proceeds were split by the U.S. Mint and a London coin dealer, Stephen Fenton, who had won that right in court after having been arrested by Secret Service agents for trying to sell the coin in the Waldorf-Astoria Hotel in Manhattan in 1996. Henrietta Holsman Fore, the director of the U.S. Mint, who witnessed the sale, said, "The monies we receive will go toward helping to pay down the debt and to fight the war on terrorism." Fenton commented that the double eagle had been on "a long historic journey, with a very satisfying ending." He added, "I am thrilled with the price." The previous numismatic record holder was an 1804 U.S. silver dollar, which sold for $4.14 million in 1999. Sotheby's partner in the one-lot auction was Stack's Rare Coins, with which it shared the customary 15 percent commission. "I have never seen as much interest in the sale of any coin in my 30 years in the business," said Lawrence R. Stack, the company's managing director. "This is the Mona Lisa of coins," said Beth Deisher, editor of Coin World, the largest weekly coin publication in the United States, with a circulation of 85,000. "It is unique. Forbidden fruit." Collectors' Web sites have surged with speculation about the sale price, and enthusiasts even organized betting pools.
Do you have any questions?
MY QUESTION: Who is the managing director of Stack's Rare Coins?

QUES: Tuesday, September 11, 2001, dawned temperate and nearly cloudless in the eastern United States. Millions of men and women readied themselves for work. Some made their way to the Twin Towers, the signature structures of the World Trade Center complex in New York City. Others went to Arlington, Virginia, to the Pentagon. Across the Potomac River, the United States Congress was back in session. At the other end of Pennsylvania Avenue, people began to line up for a White House tour. In Sarasota, Florida, President George W. Bush went for an early morning run. For those heading to an airport, weather conditions could not have been better for a safe and pleasant journey. Among the travelers were Mohamed Atta and Abdul Aziz al Omari, who arrived at the airport in Portland, Maine. Boston: American 11 and United 175. Atta and Omari boarded a 6:00 A.M. flight from Portland to Boston's Logan International Airport. When he checked in for his flight to Boston, Atta was selected by a computerized prescreening system known as CAPPS (Computer Assisted Passenger Prescreening System), created to identify passengers who should be subject to special security measures. Under security rules in place at the time, the only consequence of Atta's selection by CAPPS was that his checked bags were held off the plane until it was confirmed that he had boarded the aircraft. This did not hinder Atta's plans. Atta and Omari arrived in Boston at 6:45. Seven minutes later, Atta apparently took a call from Marwan al Shehhi, a longtime colleague who was at another terminal at Logan Airport. They spoke for three minutes. It would be their final conversation.
Do you have any questions?
MY QUESTION:
What was the weather like when President George W. Bush went for his early morning run?