Magnetism is the ability of a material to be attracted by a magnet. It also include the ability for some material to act like a magnet. No doubt youve handled refrigerator magnets. You can see some in Figure 1.28. You probably know they stick to a metal refrigerator. This is what holds your homework up. Maybe your little sisters drawings are hung on the fridge in this manner. Do magnets stick to all materials? Of course not. You have probably checked and they do not stick to other surfaces. They do not stick to wooden doors or glass windows. Wood and glass are not attracted to a magnet. Obviously, only certain materials are attracted to magnets.

Question: "What is magnetism and what is an example of this?"

Response: "Ability of a material to be attracted by glasses. Example refrigerator magnets attracting glass windows"

A: no

Heat supplies the energy that causes motion. The deeper you go into toward the Earths core, the hotter it gets. At the core it is really hot. All that heat tries to rise toward the surface. In the Mantle, the rock is partially melted and is able to move. As it is heated, the material in the mantle moves toward the surface. As the mantle material rises, it cools. When it reaches the Earths crust, it is mostly stopped. A little of the material can break through the surface, but not all. Instead, it begins to move horizontally. The mantle material moves horizontally away from a mid-ocean ridge crest. Toward the surface, the mantle material starts to cool. As it cools it sinks back down into the mantle. These areas are where deep sea trench occur. The material sinks back down to the core. The system operates like a giant conveyor belt. The motion due to heating and cooling is called convection.

Question: "Why does the system work as a conveyor belt?"

Response: "Because the material moves horizontally"

A: no

Washington The Iraqi government has agreed to let U.S. Rep. Tony Hall visit the country next week to assess a humanitarian crisis that has festered since the Gulf War of 1990, Hall's office said Monday. The Dayton Democrat, who has traveled to other crisis points including Sierra Leone and North Korea, will spend three days visiting hospitals and other facilities to seek understanding why aid has been ineffective in stemming malnourishment and other medical problems. Iraq has been under economic sanctions since the war ended, which some say have thwarted the country's ability to recover from the devastation of the bombing campaign. The Persian Gulf War destroyed much of the country's medical infrastructure, according to a report by the World Health Organization. In 1996 the WHO found that much of the population existed in a state of ''semi-starvation.'' Hall will be only the second member of Congress to travel in Iraq since the war, according to Hall's office. The last visitor was then-U.S. Rep. Bill Richardson of New Mexico, who went to help a pair of U.S. oilmen in diplomatic trouble. Hall flies to Amman, Jordan, on Friday, where he'll spend the night before driving to Iraq. Flights are not permitted into Iraq. Hall is to return to Washington on April 22. Story Filed By Cox Newspapers

Question: "Why is U.S. Rep. Tony Hall visiting Iraq?"

Response: "To help a pair of U.S. oilmen in diplomatic trouble"

A:
no