为衡量某特种车辆的性能，研究制定了行驶指数P，P=K+1000，而K的大小与平均速度v（km/h）和行驶路程s（km）有关（不考虑其他因素），K由两部分的和组成，一部分与v²成正比，另一部分与sv成正比．在实验中得到了表中的数据：

（1）用含v和s的式子表示P；

（2）当P=500，而v=50时，求s的值；

（3）当s=180时，若P值最大，求v的值．

下列有关秦始皇“皇帝”称号的说法，不正确的是

阅读理解

　     Ashia Hansen is the world indoor triple jump (三级跳)record holder. She has given up getting a place in the Great Britain team for next weekend's European Indoor Championships（锦标赛）. Hansen, whose injured leg almost brought her career（事业） to an end three years ago, won the third prize at the Union Jumps International last Wednesday. “I could look for another competition, but it's pretty pointless（无意义的）. I just have not got enough speed to jump what I want to, ” says Hansen. She still wants to take part in this year's World Championships in Osaka. She says, “I can actually smile now because I know I have not lost anything in jumping ability. It's just that the speed is not there. I've now got three months to find that before the summer season starts. ”

用一根铁丝围成一个边长4分米的正方形，这根铁丝至少有(接头处忽略不计) （   ）