Please answer with clear explanations and show the calculation process.

Magnetic Disk Case Study Some key parameters for a recent 2.5-inch drive for laptop computers. Size 80GB per surface 2/4 Platters / Heads Capacity 320 GB 120 RPS Performance 8.3 ms per rotation 1 ms Spindle speed 7200 RPM Average seek time read/write 10.5 ms / 12.0 ms Maximum seek time 19 ms Track-to-track seek time Transfer rate (surface to buffer) 54-128 MB/s Transfer rate (buffer to host) 375 MB/s Buffer memory 16 MB Power Typical 16.35 W Idle 11.68 W a 14 Task #02: Answer the following questions with some explanations: (1) Suppose a disk has 201 cylinders, numbered from 0 to 200. At some time the disk arm is at cylinder 100, and there is a queue of disk access requests for cylinders 30, 85, 90, 100, 105, 110, 135 and 145. If SSTF is being used for scheduling the disk access, the request for cylinder 90 is served after servicing number of requests. (A) 1, (B) 2, (C) 3, (D) 4 (2) Suppose the following disk request sequence (track numbers) for a disk with 100 tracks is given: 45, 20, 90, 10, 50, 60, 80, 25, 70. Assume that the initial position of the R/W head is on track 50. The additional distance that will be traversed by the R/W head when the shortest Seek Time First (SSTF) algorithm is used compared to the SCAN (Elevator) algorithm (assuming that SCAN algorithm moves towards 100 when it starts execution) is tracks. (A) 8, (B) 9, (C) 10, (D) 11