WHAT ARE COMPOSITES? A composite material combines two or more separate materials to build a single construct that combines the best properties of both, such as the silicon-germanium-arsenide composites used to build ultra-fast semiconductor chips. More common materials, such as concrete, paper, cardboard, plywood, fiberglass and bricks are all composites. The first manmade composite was probably the adobe brick. Mud or clay can be shaped and dried into a hard block, but it has little load-bearing strength. Mixing in dried grass or straw makes the bricks tougher. Reinforced concrete, in which steel rods are encased in a matrix of concrete to improve strength and load-bearing properties, is used in bridges and buildings. Tiny carbon nanotubes are beginning to serve the same purpose in building structures.
WHAT IS CAD: A computer-aided design system combines hardware and software to enable the user to design everything from furniture to cars and airplanes. The user can view a design from any angle and zoom in or out for close-up or long-distance views. CAD systems typically rely on a combination of a keyboard and conventional mouse to control what's on the screen.
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, 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.
The Materials Research Society and AVS, the Science and Technology Society, and the American Physical Society contributed to the information contained in the TV portion of this report.
