Consider a hard disk that rotates at 15000 RPM. The disk has 26 heads. Each track contains 980 sectors. Each sector contains 2 KiB (= 2048 B). Barbara determined the capacity of the disk, which is 247.86 GiB (she rounded the result slightly). How many cylinders does the disk have?

Consider a hard disk that rotates at 15000 RPM. The disk has 26 heads. Each track contains 980 sectors. Each sector contains 2 KiB (= 2048 B). Barbara determined the capacity of the disk, which is 247.86 GiB (she rounded the result slightly). How many cylinders does the disk have?

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

Consider a hard disk that rotates at 7200 RPM. The disk has 16 heads and 6200 cylinders. Each sector contains 2 KiB (= 2048 B). (a) Barbara determined the capacity of the disk, which is 198.67 GiB (she rounded the result slightly). We assume that all tracks contain the same number of sectors. How many sectors does each track contain? (b) How much time is needed to read the data from the entire disk (track per track, sector per sector) if the arm needs 3.7 ms to move to an adjacent cylinder? (c) We want the maximum data transfer rate (between the disk and the controller's buffer) to be 240 MiB/s. To achieve this goal, we are allowed to speed up the rotation. How many revolutions per minute would that disk have to do?
We are dealing with a magnetic hard disk. The disk has 15 500 cylinders and 20 heads. Each sector contains 2 KiB (= 2048 B). (a) Vida determined the capacity of the disk, which is 1082.04 GiB (she rounded the result slightly). Suppose that every track contain the same number of sectors. How many sectors does a track contain? (b) The disk arm needs 1.7 ms to move to an adjacent cylinder. Vida calculated that we need aproximately 34.13 minutes to read the entire disk. At what speed does the disk rotate (give the result in RPM)? (c) Suppose that we now change the speed of rotation to 7200 RPM. What is the maximum data transfer rate (between the disk and the controller's buffer)?
A 3T MRI scanner used is tuned for proton imaging. For a given imaging sequence applied to image a patient's leg the gradient strength is 1 G/cm, FOV is 25 cm, and matrix is 250x250. The patient has a titanium screw in their leg that causes a magnetic susceptibility change to the main magnetic field of 0.5 Gauss. How much shift is image position ( in pixels) will be seen in this part of the leg?
The outer track 0 of a hard disk has a diameter of 8cm, the innermost track 36113 has a diameter of 4cm. For simplicity, let's assume that the head is moving at a constant speed of 2m/s. The hard disk rotates at 7200 rpm, the reading time of the sectors is negligible. How long does it take to change lanes from lane 0 to lane 36113? Enter the answer in milliseconds without decimal places.
not handwritten Explain
With the MATLAB editor, please make a script m-file for the following: Simple harmonic motion is a mass connected at the end of a lossless spring. The position of the spring is defined by: y(t) = c1cos(ωt) + c2sin(ωt) Where The kinetic energy of the mass is defined by: And that c1 = 0.172 m, c2 = 0.012 m, k = 3.2 N/meter and m = 0.32 kgFor values of t from 0 to 8.25 sec in increments of 0.05 secMake variables c1, c2, k and m and assign valuesPlease Calculate the value of omega in rad/secFind the values of y in cm and KE in JoulesUsing subplots make two side by side plots within one figure:Display the results on a x-y scatter plot With t the independent variable plotted on the x axisAnd y the dependent variable plotted on the y axisInclude units within the labels Show the results on a x-y scatter plot With t the independent variable plotted on the x axisAnd KE the dependent variable plotted on the y axisInclude units within the labels
As we showed, the horizontal displacements ξi of masses i = 1 . . . N satisfy equations of mo- tion md2ξ1 =k(ξ2−ξ1)+F1, dt2 md2ξi =k(ξi+1−ξi)+k(ξi−1−ξi)+Fi, dt2 md2ξN =k(ξN−1−ξN)+FN. dt2 where m is the mass, k is the spring constant, and Fi is the external force on mass i. In Exam- ple 6.2 we showed how these equations could be solved by guessing a form for the solution and using a matrix method. Here we'll solve them more directly. a) Write a python program to solve for the motion of the masses using the fourth-order Runge- Kutta method for the case we studied previously where m = 1 and k = 6, and the driving forces are all zero except for F1 = cos ωt with ω = 2. Plot your solutions for the displace- mentsξi ofallthemassesasafunctionoftimefromt=0tot=20onthesameplot. Write your program to work with general N, but test it out for small values—N = 5 is a reasonable choice. You will need first of all to convert the N second-order equations of motion into 2N first- order equations.…
Given x=0.8cos(2 n 100 1): Write MATLAB code to plot 2 periods of x with 41 points (i.e, the size of x is 41) as shown 0.6 04 02 02 04 0 002 0004 0.006 0.006 001 0.012 0.014 0016 0.018 002
A main-sequence star is 8.7 times more massive than the Sun. Its luminosity is 1942 times that of the Sun. If the Sun's main-sequence lifetime is 10 billion years, how many years will this star live? years
... A centered dataset with n = 116 observations and p = 9 variables was analysed to reduce its dimensionality. The following is a list of singular eigenvalues of X in decreasing order, that is d₁, d2, . . . , dg: 399.1338, 192.1412, 173.0043, 161.6635, 158.0541, 146.6826, 140.0039, 134.1633, 121.1941. A) Compute and write the numerical value of the eigenvalue 4 of Σ. This eigenvalue is located in the position (4, 4) of the matrix A and is simultaneously the sample variance of the score PC4: B) Compute and write the percentage of total variability explained by the Principal component PC4. The number you write should be between 0 and 100 and you should include decimals in your answer. C) A threshold of total variability explained has been set at 80%. How many principal components must you select? Write your answer (integer value).
The electric flux density D at the point M (0,4,0) in the region about a uniform line charge of 1 nC/m lying along the z axis in free space is: Select one: a. None of the above b. 0.6366 nC/m c. 0.2387 nC/m d. 0.039 nC/m e. 0.1 nC/m
Please work out question 28 and show work for explanation of how you came up with your answer.