Problem: 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 does GMT stand for and how it is determined?"

Answer: "Greenwich Mean Time and it is determined by Zero longitude runs through Greenwich, England"
Answer: yes

Problem: 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: "Which two factors were different between the three other hijacked planes and United 93?"

Answer: "the day of the takeover"
Answer: no

Problem: Have you are burned something on the stove or in the oven? Do you know why things burn? It all has to do with temperature. Changes in matter are affected by temperature. For example, what if you place a cake in the oven and you leave it in too long? What do you think will happen? Thats right, it will probably burn. The same thing will happen if the oven setting is too high and you apply too much heat. In either case, heat has affected the rate of change in matter. Its probably obvious that when the temperature is increased a chemical change, like cooking, will occur faster. What about a physical change? Are physical changes affected by temperature? Most of us have seen steam rising off a wet road after a summer rainstorm. This happens because the road surface is very warm. The warm road and warm air temperature causes the water to evaporate quickly. The liquid water is turning into water vapor, but it is still water. The evaporation of water is a physical change. So yes, temperature affects the rate that physical change occurs.

Question: "What is causing cakes in the oven to burn and water from the road to evaporate on the hot day?"

Answer: "Raise in temperature"
Answer:
yes