Compact discs. When a compact disc (CD) is playing, the angular speed of the turntable is adjusted so that the laser beam, which reads the digital information encoded in the surface of the disc, maintains a constant tangential speed. The laser begins tracking at the inside of the disc and spirals outward as the disc plays, while the angular speed of the disc varies between 500 rpm and 200 rpm. A certain CD (see Figure 9.34 ) plays for 74 minutes and has a playing area of outer diameter 12.1 cm (which is also essentially the outside diameter of the disc). (a) What is the tangential speed of the laser beam? (b) What is the diameter of the inside of the playing area of this CD? (c) What is the angular acceleration of the CD while it is playing, assuming it to be constant? Figure 9.34 Problem 59.
Compact discs. When a compact disc (CD) is playing, the angular speed of the turntable is adjusted so that the laser beam, which reads the digital information encoded in the surface of the disc, maintains a constant tangential speed. The laser begins tracking at the inside of the disc and spirals outward as the disc plays, while the angular speed of the disc varies between 500 rpm and 200 rpm. A certain CD (see Figure 9.34 ) plays for 74 minutes and has a playing area of outer diameter 12.1 cm (which is also essentially the outside diameter of the disc). (a) What is the tangential speed of the laser beam? (b) What is the diameter of the inside of the playing area of this CD? (c) What is the angular acceleration of the CD while it is playing, assuming it to be constant? Figure 9.34 Problem 59.
Compact discs. When a compact disc (CD) is playing, the angular speed of the turntable is adjusted so that the laser beam, which reads the digital information encoded in the surface of the disc, maintains a constant tangential speed. The laser begins tracking at the inside of the disc and spirals outward as the disc plays, while the angular speed of the disc varies between 500 rpm and 200 rpm. A certain CD (see Figure 9.34) plays for 74 minutes and has a playing area of outer diameter 12.1 cm (which is also essentially the outside diameter of the disc). (a) What is the tangential speed of the laser beam? (b) What is the diameter of the inside of the playing area of this CD? (c) What is the angular acceleration of the CD while it is playing, assuming it to be constant?
Figure 9.34 Problem 59.
Definition Definition Rate of change of angular velocity. Angular acceleration indicates how fast the angular velocity changes over time. It is a vector quantity and has both magnitude and direction. Magnitude is represented by the length of the vector and direction is represented by the right-hand thumb rule. An angular acceleration vector will be always perpendicular to the plane of rotation. Angular acceleration is generally denoted by the Greek letter α and its SI unit is rad/s 2 .
suggest a reason ultrasound cleaning is better than cleaning by hand?
Checkpoint 4
The figure shows four orientations of an electric di-
pole in an external electric field. Rank the orienta-
tions according to (a) the magnitude of the torque
on the dipole and (b) the potential energy of the di-
pole, greatest first.
(1)
(2)
E
(4)
What is integrated science.
What is fractional distillation
What is simple distillation
Chapter 9 Solutions
College Physics Volume 1 (Chs. 1-16); Mastering Physics with Pearson eText -- ValuePack Access Card -- for College Physics (10th Edition)
Genetic Analysis: An Integrated Approach (3rd Edition)
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