Consider a disk with a sector size of $512$ bytes, $50$ sectors per track, $2000$ tracks per surface and five double-sided platters (i.e. $10$ surfaces). The disk platters rotate at $5400$ rpm. The average seek time is $10$ msec. A block size is chosen as $1024$ bytes.
A file containing $100,000$ records of $100$ bytes each is to be stored on this disk, and no record is allowed to span two blocks. Then, the rotational latency of the disk is ________ seconds.