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.

Question: "Why do your hands become warmer when you rub them together?"

OPTIONS:
- no
- yes

Answer: "From electric current"

Response: no

(CNN) -- Beyond skateboards, Silicon Valley and hippies, California has a trendsetting streak of a different kind. The state has been first to pass major public health initiatives that have spread throughout the country. California was first to require smog checks for clean air, pass anti-tobacco initiatives and bike helmets laws. While these laws were met with skepticism and ridicule, they've often become standard practice in other states. The Golden State was first to ban smoking in workplaces, bars and restaurants in 1998. Now similar rules exist throughout the country. Some advocates tout the state as a forward-thinking vanguard in which its health and safety laws are routinely emulated by other states. "There have been progressive legislations in tobacco, environment and obesity prevention," said Mark Horton, a lecturer at the University of California Berkeley School of Public Health. "In some respect, the rest of the country looks to California as a laboratory for moving forward with those various types of initiatives." But some critics liken the Golden State to a nanny state. California has 151,002 health and safety laws. "It never ends," said Laer Pearce, who works in public affairs in Orange County. "Every year, several hundred bills come through and dozens of them tell us how to live our lives." Starting in January, 760 new California laws went into effect -- for example, the importing of shark fins is prohibited, student athletes are required to have medical clearance after suffering a head injury, teens are banned from using tanning booths and the sale of caffeinated beer is forbidden. There's a perception that California has "more folks who are health-oriented and more health-minded," said Horton, former director of the California Department of Public Health. It's not just workout fanatics hanging out at Muscle Beach, Sierra Club members hiking mountains or the uber-health-conscious touting organic foods. Californians in general tend to have healthier habits, ranking 10th for physical activity, fourth for healthy blood pressure and fifth for a diet high in fruits and vegetables compared with other states, according to America's Health Rankings.

Question: "What rules exist throughout the country because of a California ban?"

OPTIONS:
- no
- yes

Answer: "Ban smoking in workplaces, bars and restaurants in 1998"

Response: yes

How would the universe look without gravity? It would have no planets and no stars. Thats how it looked when it was young. When the universe was young, there was only gas and dust. From this gas and dust, everything we now see was made. How were stars and planets created from just gas and dust? The answer is gravity. The same gravity that holds you down on Earth. The same force that causes your pencil to roll off your desk. The same force that causes it to fall to the floor. The invisible force of gravity caused dust and gas particles to be pulled together. This force is what formed all the objects in our solar system. This force formed the smallest moons. It also formed our Sun. This force caused more than just our solar system to form. It caused all the other solar systems to form. It caused the formation of all the galaxies of the universe.

Question: "Did the universe always have a sun?"

OPTIONS:
- no
- yes

Answer: "No, the universe did not have planets or stars, only gas and dust, from which the Sun was created"

Response: yes

Assisting Zionist causes Einstein was a figurehead leader in helping establish the Hebrew University of Jerusalem, which opened in 1925, and was among its first Board of Governors. Earlier, in 1921, he was asked by the biochemist and president of the World Zionist Organization, Chaim Weizmann, to help raise funds for the planned university. He also submitted various suggestions as to its initial programs. Among those, he advised first creating an Institute of Agriculture in order to settle the undeveloped land. That should be followed, he suggested, by a Chemical Institute and an Institute of Microbiology, to fight the various ongoing epidemics such as malaria, which he called an "evil" that was undermining a third of the country's development. Establishing an Oriental Studies Institute, to include language courses given in both Hebrew and Arabic, for scientific exploration of the country and its historical monuments, was also important. Chaim Weizmann later became Israel's first president. Upon his death while in office in November 1952 and at the urging of Ezriel Carlebach, Prime Minister David Ben-Gurion offered Einstein the position of President of Israel, a mostly ceremonial post. The offer was presented by Israel's ambassador in Washington, Abba Eban, who explained that the offer "embodies the deepest respect which the Jewish people can repose in any of its sons". Einstein declined, and wrote in his response that he was "deeply moved", and "at once saddened and ashamed" that he could not accept it.

Question: "What are the ways Einstein contributed to the development of the Hebrew University of Jerusalem?"

OPTIONS:
- no
- yes

Answer: "Establishing an Oriental Studies Institute"

Response:
yes