Question:
Right after the Pentagon was hit, NEADS learned of another possible hijacked aircraft. It was an aircraft that in fact had not been hijacked at all. After the second World Trade Center crash, Boston Center managers recognized that both aircraft were transcontinental 767 jetliners that had departed Logan Airport. Remembering the "we have some planes" remark, Boston Center guessed that Delta 1989 might also be hijacked. Boston Center called NEADS at 9:41 and identified Delta 1989, a 767 jet that had left Logan Airport for Las Vegas, as a possible hijack. NEADS warned the FAA's Cleveland Center to watch Delta 1989. The Command Center and FAA headquarters watched it too. During the course of the morning, there were multiple erroneous reports of hijacked aircraft. The report of American 11 heading south was the first; Delta 1989 was the second. NEADS never lost track of Delta 1989, and even ordered fighter aircraft from Ohio and Michigan to intercept it. The flight never turned off its transponder. NEADS soon learned that the aircraft was not hijacked, and tracked Delta 1989 as it reversed course over Toledo, headed east, and landed in Cleveland. But another aircraft was heading toward Washington, an aircraft about which NORAD had heard nothing: United 93. United Airlines Flight 93 FAA Awareness. At 9:27, after having been in the air for 45 minutes, United 93 acknowledged a transmission from the Cleveland Center controller. This was the last normal contact the FAA had with the flight. Less than a minute later, the Cleveland controller and the pilots of aircraft in the vicinity heard "a radio transmission of unintelligible sounds of possible screaming or a struggle from an unknown origin." The controller responded, seconds later: "Somebody call Cleveland?"This was followed by a second radio transmission, with sounds of screaming. After reading the above, is "A 767 jet" the correct answer to the question "How did the Cleveland controller respond to a transmission that seemed to signify trouble?"? OPTIONS:
- no
- yes

Answer:
yes

Question:
Sometimes traits can vary from parent to offspring. These changes are due to mutations. Mutations are a random change. Mutations are natural. Some mutations are harmful. In this case, the organism may not live to reproduce. The trait will not be passed onto offspring. Others variations in traits have no effect on survival. Can some mutations be good for a living thing? Other mutations can have great benefits. Imagine being the first moth that can blend into its background. It would have a better chance of survival. A living thing that survives is likely to have offspring. If it does, it may pass the new trait on to its offspring. Thats good news for the offspring. The offspring may be more likely to survive. Mutations are one way living things adapt to new conditions. After reading the above, is "Picking up the worst traits" the correct answer to the question "What are mutations good for?"? OPTIONS:
- no
- yes

Answer:
no

Question:
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. After reading the above, is "Pushing the swing toward herself" the correct answer to the question "What is the direction of force in which the girl is pushing a swing in Figure 1.1?"? OPTIONS:
- no
- yes

Answer:
no

Question:
So what is gravity? A typical definition of gravity is that it is a force. It causes an attraction between two masses. According to this definition, anything that has mass exerts a force. Any object exerts gravity on other objects. It does not matter how small it is, it has gravity. The more matter an object has, the more gravity it has. Your pencil has a tiny bit of gravity, but far too little to notice. What about a planet? It would have a lot of gravity. An objects gravity exerts a pull on other objects. Friction only occurs between objects that are touching. Gravity can act between objects that are not touching. In fact, gravity can act over very long distances. Where else can you feel gravity? After reading the above, is "Friction only occurs between objects that are not touching" the correct answer to the question "Does size matter when it comes to gravity?"? OPTIONS:
- no
- yes

Answer:
no