Input: You know that friction also causes heat. Think about when you rub your hands together. It is friction that makes them warm. But why does this happen? Friction causes the molecules on rubbing surfaces to move faster. Faster moving particles have more heat energy. Heat from friction can be useful. Can you think of other places where you might find friction? Friction also lets you light a match. Heat from friction can also cause problems. It can cause a car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts. This coating of oil makes them slippery. When things are slippery there is less friction. Have you ever seen a sign that says, slippery when wet? This too has to do with friction. Water, like oil, can reduce friction. The wet surface may allow your shoes to slide more easily.

Does the response "They get moist" correctly answer the question "What happens when you rub your hands together?"?

OPTIONS:
- no
- yes
***
Output: no

Electric charge is a physical property. It occurs between particles or objects. It causes them to attract or repel each other. They do not even have to touch. This is unlike the typical push or pull you may be familiar with. All electric charge is based on the protons and electrons in atoms. A proton has a positive electric charge. An electron has a negative electric charge. Forces on Charged Objects Most atoms are balanced electrically. They have the same number of positive and negative charges. Therefore, the number of protons equals the number of electrons. Neutrons do not matter as they have no charge. When an object loses some electrons, it becomes positively charged. There are now more protons than electrons inside the atom. The lost electrons may remain free. Or, they may attach to another object. The new object now has more electrons than protons. It then becomes negatively charged.

Question: "Why does an object's charge become positive?"

OPTIONS:
- no
- yes

Answer: "When an object loses electrons"

Response: yes

At 8:38, Ong told Gonzalez that the plane was flying erratically again. Around this time Sweeney told Woodward that the hijackers were Middle Easterners, naming three of their seat numbers. One spoke very little English and one spoke excellent English. The hijackers had gained entry to the cockpit, and she did not know how. The aircraft was in a rapid descent. At 8:41, Sweeney told Woodward that passengers in coach were under the impression that there was a routine medical emergency in first class. Other flight attendants were busy at duties such as getting medical supplies while Ong and Sweeney were reporting the events. At 8:41, in American's operations center, a colleague told Marquis that the air traffic controllers declared Flight 11 a hijacking and "think he's [American 11] headed toward Kennedy [airport in New York City]. They're moving everybody out of the way. They seem to have him on a primary radar. They seem to think that he is descending." At 8:44, Gonzalez reported losing phone contact with Ong. About this same time Sweeney reported to Woodward, "Something is wrong. We are in a rapid descent . we are all over the place." Woodward asked Sweeney to look out the window to see if she could determine where they were.

Question: "At what time did Sweeney tell Woodward that the hijackers were Middle Easterners, naming three of their seat numbers."

Response: "On take off"
OPTIONS:
- no
- yes

A: no

Problem: The grant also will help victims go through court proceedings after losing a job or being evicted because of an abuser's actions, Xanthopoulos said. "It's going to help the victims, but it's also going to help their children," he said. More than 270 domestic violence assaults in Madison County were reported last year, according to Tennessee Bureau of Investigation statistics. In Jackson, more than 730 domestic violence assaults were reported last year, according to records. "Domestic violence is certainly on the increase and we need to do something to curve that. I see this as helping that," Madison County Sheriff David Woolfork said of the grant. Domestic violence accounted for five of 12 murders in 2001 in Jackson, police have said. And the increase in calls prompted Jackson Police Chief Rick Staples in March to form a focus group to determine if police officers need to make changes in their response to domestic calls.

Question: "Who did Xanthnopoulos say the grant would help?"

Answer: "Police focus groups"

OPTIONS:
- no
- yes
Answer: no

Sound waves are mechanical waves. They can travel only through matter. They cannot travel through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could not be heard. Thats because the sound couldnt travel without air particles to transfer the sound energy. Is there any other place where sound cannot be heard? Here is a hint: is there any other place that does not have air molecules? Thats right, in space sound cannot be transferred. So can astronauts hear each other? Yes, they can, because they are in enclosed space stations or pressurized suits.In both cases, they are surrounded by air molecules. If they left their space ship and did not use their electronics, they would not be able to hear each other. Next time you watch a science fiction movie, think about this factoid. When spaceships are destroyed by hostile alien beings, there would be no sound heard. Sound waves can travel through many kinds of matter.

Question: "In Boyle's experiment, what did he do to make the clock stop being heard while in the jar?"

Response: "Boiled the air"
OPTIONS:
- no
- yes

A:
no