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تستخدم محركات الأقراص المضغوطة آلية تعمل على إبطاء القرص عندما يكون شعاع الليزر بالقرب من مركز القرص وتسريع القرص عندما يكون شعاع الليزر بالقرب من الحافة الخارجية.
Moumen Xavi Amigo
Wiki User
∙ 14y agoThe CD drives uses a mechanism that slows down the disc when the laser beam is near the center of the disc and speeds up the disc when the laser beam is near the outer edge.
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What do you need in order to read each sector on the spiral of a CD at a constant?
Linear Velocity.
How does constant angular velocity apply to CD standards?
If a stationary base reference line and a zero line on the disk both extend from the outer edge of the disk to the center of rotation, constant angular velocity will ensure the periodic angle changes between the two lines remains a constant. This allows the CD to be played smoothly.
A single speed CD-ROM drive transfersdata at what rate?
150 KB/s.Reference:The first generation of "single-speed" CD-ROM drives were based on the design of audio CD drives, employing constant linear velocity (CLV) technology to spin a disc at the same speed as an audio CD which, with error correction, meant 150 KBps.Source: http://www.pctechguide.com/32CD-ROM_CLV.htm
Define constant angular velocity and explain how it is applies to a CD?
Angular velocity is the measure of angular displacement (in one or the opposite) direction over a unit period of time. In the context of CDs , one unit in which this can be measured is the number of revolutions per second. A constant angular velocity means that the CD is turning through the same angle each second.
With what kind of constant velocity the disc rotates at a constant speed?
"Some later CD drives use CLV technology in combination with constant angular velocity (CAV). With CAV, the disc rotates at a constant speed, just as is done with hard drives."(pg 459, A+ Guide to Managing and Maintaining Your PC)
Define constant linear velocity and explain how it applies to CD standards?
Constant angular velocity of a rotating disk means that, given a stationary base reference line and a zero line on the disk, both extending from the center of rotation to the outside edge of the disk, the periodic change in angle between the two lines remains a constant. Such a disk will have constant angular velocity (CAV) if its rate of rotation or revolutions per minute (RPM) remains constant.While it would be technically possible to have the linear velocity of the disk remain constant by gradually decreasing the speed of rotation as the player head moves across the disk (because the outer paths are longer than the inner ones), this would make things more complicated both for the recording and playback machines, and therefore more expensive.The paths of information on a CD (or DVD) are analogous to the grooves on an LP recording. The recording and playback heads move across the disk (CD or LP) as it rotates. Actually, of course, there is only one spiral path or groove; on an LP, it goes from the outside edge toward the center; on a CD/DVD, it goes in the opposite direction. In deciding on the parameters for the LP and CD, engineers had to involve the amount of data to be recorded and the spacing required to record that data versus the size of the disk, the speed of rotation, the data capacity of the disk material, and the sensitivity of both the recording and playback heads. ---- The above answer defines Constant Angular Velocity (CAV), not Constant Linear Velocity. The following is the definition to Constant Linear Velocity (CLV): "Constant Linear Velocity (CLV) is a CD-ROM (Compact Disc - Read Only Memory) format in which the spacing of data is consistent on the CD, but the speed of the disc varies on whether the data being read is near the cent or the edge of the disc." During CLV, in order to create the effect of constant speed as the CD turns, the CD drive uses a mechanism that slows down the disc when the laser beam is near the center of the disc, and speeds up the disc when the laser beam is near the outer edge. Thus, the beam is over a sector for the same amount of time, no matter where the sector is.
What kind of velocity causes a disc to rotate at a constant speed?
Uniform-Pertaining to computers-"Some later CD drives use CLV technology in combination with constant angular velocity (CAV). With CAV, the disc rotates at a constant speed, just as is done with hard drives."(pg 459, A+ Guide to Managing and Maintaining Your PC)
Define constant angular velocity and explain how it applies to CD standards?
Constant angular velocity of a rotating disk means that, given a stationary base reference line and a zero line on the disk, both extending from the center of rotation to the outside edge of the disk, the periodic change in angle between the two lines remains a constant. Such a disk will have constant angular velocity (CAV) if its rate of rotation or revolutions per minute (RPM) remains constant.While it would be technically possible to have the linear velocity of the disk remain constant by gradually decreasing the speed of rotation as the player head moves across the disk (because the outer paths are longer than the inner ones), this would make things more complicated both for the recording and playback machines, and therefore more expensive.The paths of information on a CD (or DVD) are analogous to the grooves on an LP recording. The recording and playback heads move across the disk (CD or LP) as it rotates. Actually, of course, there is only one spiral path or groove; on an LP, it goes from the outside edge toward the center; on a CD/DVD, it goes in the opposite direction. In deciding on the parameters for the LP and CD, engineers had to involve the amount of data to be recorded and the spacing required to record that data versus the size of the disk, the speed of rotation, the data capacity of the disk material, and the sensitivity of both the recording and playback heads.The result of this engineering was set as the standard for recording audio LP's and CD's and, later, DVD's.
v.Does high fluid velocity and low fluid velocity affect the value of Cd?
Yes
What is purpose of angular velocity?
In http://www.answers.com/topic/optical-storage, constant angular velocity (CAV) is a qualifier for the rated speed of an http://www.answers.com/topic/optical-disc-drive, and may also be applied to the writing speed of recordable http://www.answers.com/topic/optical-disc. A drive or disc operating in CAV mode maintains a constant http://www.answers.com/topic/angular-velocity, contrasted with a http://www.answers.com/topic/clv (CLV). When playing back music, a http://www.answers.com/topic/compact-disc (CD) employs CLV to maintain a constant data rate. The motor speed decreases from 495 to 212 rpm as the read head moves away from the center to keep the disc moving past the read head at a constant linear velocity. High speed CD and DVD drives use CAV. CAV was used in the LaserDisc format for interactive titles, as well as special editions of certain films. CAV allowed for perfect still frames, as well as random access to any given frame on a disc. Playing time, however, was cut in half from 60 minutes to 30 minutes. CAV is used with Nintendo GameCube Game Disc and Wii Optical
What has the author Eugene A Herman written?
Eugene A. Herman has written: 'Visual Linear Algebra with Tutorial CD and Student Solutions Manual Set' 'Visual Linear Algebra'
What is the formula for calculating Velocity?
Mathematically, terminal velocity-without considering buoyancy effects-is given bywhereVt = terminal velocity,m = mass of the falling object,g = acceleration due to gravity,Cd = drag coefficient,ρ = density of the fluid through which the object is falling, andA = projected area of the object.Anand Kumar GuptaResearch ScholarCSIR Laboratory
