How can you describe your location? You might use a familiar system. You might say, 'I live at 1234 Main Street, Springfield, Ohio.' You could also say, 'I live right behind the Elementary School.' This method uses the school as a point of reference. Another example is, I am at the corner of Maple Street and Main Street. Both streets may be a good reference for anyone living in your town. Scientists must be able to pinpoint a feature they are studying. Scientists use a special system to describe locations. They use latitude and longitude as a reference. Lines of latitude and longitude form a grid. You may have used a grid system while doing graphing. This grid is centered on a reference point. Zero latitude is the equator. Lines of latitude run east to west. They divide the Earth from North to South. Lines of longitude run from north to south. They divide the Earth from East to West. Zero longitude runs through Greenwich, England. You may have heard the term, Greenwich Mean Time, or GMT. The system of latitude and longitude works well for objects that do not move.

Question: "What reference points do scientists use to describe location?"

Answer: "North pole"

Response: no

The hijackers attacked at 9:28. While traveling 35,000 feet above eastern Ohio, United 93 suddenly dropped 700 feet. Eleven seconds into the descent, the FAA's air traffic control center in Cleveland received the first of two radio transmissions from the aircraft. During the first broadcast, the captain or first officer could be heard declaring "Mayday" amid the sounds of a physical struggle in the cockpit. The second radio transmission, 35 seconds later, indicated that the fight was continuing. The captain or first officer could be heard shouting:" Hey get out of here-get out of here-get out of here." On the morning of 9/11, there were only 37 passengers on United 93-33 in addition to the 4 hijackers. This was below the norm for Tuesday mornings during the summer of 2001. But there is no evidence that the hijackers manipulated passenger levels or purchased additional seats to facilitate their operation. The terrorists who hijacked three other commercial flights on 9/11 operated in five-man teams. They initiated their cockpit takeover within 30 minutes of takeoff. On Flight 93, however, the takeover took place 46 minutes after takeoff and there were only four hijackers. The operative likely intended to round out the team for this flight, Mohamed al Kahtani, had been refused entry by a suspicious immigration inspector at Florida's Orlando International Airport in August. Because several passengers on United 93 described three hijackers on the plane, not four, some have wondered whether one of the hijackers had been able to use the cockpit jump seat from the outset of the flight. FAA rules allow use of this seat by documented and approved individuals, usually air carrier or FAA personnel. We have found no evidence indicating that one of the hijackers, or anyone else, sat there on this flight. All the hijackers had assigned seats in first class, and they seem to have used them. We believe it is more likely that Jarrah, the crucial pilot-trained member of their team, remained seated and inconspicuous until after the cockpit was seized; and once inside, he would not have been visible to the passengers.

Question: "How much longer was the United 93 takeover than their previous attemps?"

Answer: "30 seconds"

Response: no

What if two children push a swing at the same time? Would the swing go higher? Yes, together their force would be more. It is common for forces to be combined. Most objects on Earth have at least two forces acting on them. Do you know what one of them is? Of course, that force is gravity. How many forces do you have on you right now? Gravity pulls you down toward the center of Earth. Your legs exert a downward force. They hold you up against the pull of gravity. Consider the example in Figure 1.3. A book is resting on a table. Gravity pulls the book downward. It has a force of 20 newtons. At the same time, the table pushes the book upward. Its force is also 20 newtons. The table opposes the pull of gravity.

Question: "What direction is the force of a table on a book that is resting on it?"

Answer: "Upwards"

Response: yes

U.S. Secretary of State Colin Powell arrived here on Tuesday night for meetings with fellow foreign ministers aimed at solidifying a second front, in Southeast Asia, in the campaign against global terrorism. But he has had to balance that goal with longstanding concerns about human rights abuses in the region. In meetings on Tuesday in Malaysia and Singapore before touching down in this oil-producing sultanate for two days of talks with members of the Association of South East Asian Nations, Powell said he repeatedly raised the issue. "We still believe strongly in human rights, and that everything we do has to be consistent with universal standards of human rights," he said. But at a news conference in Singapore, Powell hinted that the Bush administration was ready to discuss resuming military cooperation with Indonesia, the world's most populous Muslim nation and a sometimes reluctant partner in the efforts to crack down on militant Islamic groups. The United States cut virtually all military links with Indonesia in 1999 after its forces were implicated in the violence that swept East Timor after that territory voted for independence. On Thursday, Powell and representatives of the nations of the Asian group, including Indonesia, are expected to sign a declaration promising cooperation to prevent terrorism by sharing information, blocking funds, tightening borders and making it hard to use forged travel papers. "We recognized that terrorism is a global threat and that the disturbing acts of terrorism and transnational crimes, which continue to threaten world peace and stability, must be tackled by the international community," the ministers said in a communique on Tuesday. Powell is among the representatives from 13 nations outside Southeast Asia, including China, Japan and Russia, that are taking part in the annual meeting of the group's regional forum. Terrorism dominates the agenda, though the possibility of a meeting here between Powell and his North Korean counterpart, Paek Nam Sun, has generated the most news. It would be the highest-level contact between the United States and North Korea since President Bush took office. Powell heads to Indonesia's capital, Jakarta, late on Thursday before finishing a weeklong trip through the region in the Philippines on Saturday. He said that when he arrives in Jakarta, he will have "some ideas and some initiatives" to present to President Megawati Sukarnoputri. Indonesia is already receiving $400,000 in the current fiscal year for civilian training programs and is to receive a like amount next year; and the United States expects to provide an additional $16 million this year to train police officers in counterterrorism. At the same time, the Pentagon is reviewing how to allocate another $17 million in "counterterrorism fellowships," some of which could go to Indonesia. But a senior State Department official also acknowledged that some in the administration and Congress are pushing for more direct military cooperation, which would require congressional approval. "I think they recognize the danger that we all face and I think they have been cooperating more fully with us as time goes by, and I'm quite sure that Mrs. Megawati is committed to this cause," Powell said in Singapore. He met there with Prime Minister Goh Chok Tong, who endorsed the idea of renewed military ties between the United States and Indonesia as an important step in stabilizing that country.

Question: "Who is Paek Nam Sun?"

Answer: "Prime Minister of Japan"

Response:
no