The inner diameter of the water pipe is 2 cm and the velocity of water in the pipe is 8 cm per second. A student went to the sink to wash his hands and forgot to turn off the faucet when he left. After 5 minutes, another student found out and turned off the faucet. How many liters of water was wasted in these 5 minutes?
自来水管的内直径是2厘米，水管内水的流速是每秒8厘米．一位同学去水池洗手，走时忘记关掉水龙头，5分钟后另一位同学发现并关掉水龙头，这5分钟共浪费多少升水．
<result>7.536</result>