我要写关于seat bell(安全带)得
用英文,大概500words左右
内容要包括: attach suiable references and diagrams
參考答案:How Air Bags Work
To have a frontal (driver or passenger) air bag deploy, certain criteria must be met. One of these criteria is that the frontal impact must be within a 60-degree window, occurring within 30 degrees from the vehicle's centerline. Another key element is that the crash forces are equivalent to a head-on collision with an immovable barrier at 10-15 miles per hour. Because a typical automobile accident only lasts about 0.125 (1/8th) of a second, air bags deploy within 15 to 20ms after the initial crash impact. To create a protective cushion between the occupant and the vehicle's interior, the air bag inflates at speeds up to 200 mph within approximately 30ms after impact. This allows the occupant to contact a fully inflated bag within approximately 45 to 50ms after the initial crash impact. Approximately 100ms after impact the bag deflates.不够具体的话可以去下面的网站
