WHAT HAPPENS DURING A CRASH? The laws of physics say that an object in motion will stay in motion, with the same speed and direction, unless it is acted upon by an outside force. So if you are traveling at 60 MPH and your car hits a solid wall and comes to an immediate stop, your body will continue going at 60 MPH until it is stopped by, say, a seatbelt, airbag, or, at worst, a windshield. If the car has a rigid body, the rapid deceleration caused by the impact will produce injuries and fatalities. Because the stopping time is only a split second, the force on the passengers is very high.
WHAT IS STEEL: Steel describes an entire family of metals, all of them alloys in which iron is mixed with carbon and other elements. Steel is used in just about every area of our lives: in cars, in construction, in appliances like refrigerators and washing machines, even to make steel toecaps for protective boots and scalpels for medical surgery. Steel is environmentally quite friendly: it is easily recycled, highly durable, and uses much less energy to produce than other materials.
WHERE STEEL GETS ITS PROPERTIES: How hard steel is depends on how much carbon is inside. For instance, the steel used to manufacture a pair of scissors contains almost 20 times as much carbon as the steel used in a soda can. But no steel contains more than 1.5 percent carbon. Heat can also affect steel's properties. If you cool a red-hot piece of steel very quickly in cold water, it will become harder and more brittle. The same piece of metal could be made softer by keeping it at a high heat for a longer period of time and then cooling it slowly.
The Materials Research Society contributed to the information contained in the TV portion of this report.