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CHAPTER
Dynamics of a
13 Rigid Body
CONCEPTS IN CONTEXT Concepts
in
The Gravity Probe B satellite, containing four high-precision gyroscopes, Context
13.1 Work, Energy, and Power in was recently placed in orbit by a rocket.These gyroscopes are used for a del-
Rotational Motion; Torque icate test of Einstein’s theory of General Relativity. The rotor of one of
13.2 The Equation of Rotational these gyroscopes is shown here. It consists of a nearly perfect sphere of
Motion quartz, 3.8 cm in diameter, suspended electrically and spinning at 10000
13.3 Angular Momentum and Its revolutions per minute.
Conservation Some of the questions we can address with the concepts developed in
this chapter are:
13.4 Torque and Angular
Momentum as Vectors
? When initially placed in orbit, the rotor is at rest. What torque and
what force are needed to spin up this gyroscope with a given angular
acceleration? (Example 4, page 401)
? A rotating body, such as this rotor, has not only kinetic energy,
but also an angular momentum, which is the rotational analog of the
linear momentum introduced in Chapter 10. How is the angular
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