题目

Millions of people are now using what are called“peer-to-peer”networks. Basically, you link your computer to other computers all across the country, mostly so you can give something in exchange for music for free.“But here's the problem,”“Early Show”Consumer Correspondent Susan Koeppen says as part of the broadcast's series, “Somebody's Watching You”: thieves are using the same networks, and they're not interested in music－they're seeking access to your financial information.   Beth Pope learned the hard way. When she put peer-to-peer software on her computer, she had one go12．研究表明，一般人的刹车反应时间（即图甲中“反应过程”所用时间）t0=0.4s，但饮酒会导致反应时间延长．在某次试验中，志愿者少量饮酒后驾车以v0=72km/h的速度在试验场的水平路面上匀速行驶，从发现情况到汽车停止，行驶距离L=39m．减速过程中汽车位移s与速度v的关系曲线如图乙所示，此过程可视为匀变速直线运动．取重力加速度的大小g=10m/s2．求：（1）减速过程汽车加速度的大小；（2）饮酒使志愿者的反应时间比一般人增加了多少．