operating systems true or false $86.$ A seek on a modern disk drive could take around $1$ second. $87.$ With a $7200$ RPM disk, the average rotation time for a random read is expected to be around $8\mathrm{.}3$ ms$.88.$ On a modern disk, a workload of sequential reads will be about twice as fast as a workload of random writes. $89.$ Track skew accounts for the amount a disk rotates while the r$/$w head seeks for one track. $90.$ Shortest$-$positioning$-$time$-$first can be implemented more accurately inside of a disk than within the OS$.91.$ Shortest$-$positioning$-$time$-$first treats $1/0$ requests from different processes fairly