ISSN:0002-9505    

DOI:10.1119/1.17990

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.17991

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.17993

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.18070

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.17964

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.17965

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

The many oscillations of a rigid rod—pendular, bifilar, torsional, coupled, nonlinear (including purex3), and chaotic—provide interesting opportunities for experimental and theoretical investigations in introductory, intermediate, and advanced mechanics courses. Because of the rod’s simple geometry, precise expressions for the periods of its oscillations can be calculated, allowing comparisons between theory and experiment to within 0.5%. At this level of precision, the finite diameter of the pin upon which the rod oscillates has an observable effect on the period. A derivation is given of this effect, and applied to a ring oscillating on rods of various diameters. The large‐angle oscillations of the bifilar pendulum are shown to depart by a measurable amount from the large‐angle oscillations of the physical pendulum. The unequal‐arm bifilar pendulum couples torsional and pendular modes in a calculable way. The vertical bifilar pendulum is a double pendulum with calculable coupled oscillations for small amplitudes and chaotic oscillations for large amplitudes. Other oscillators that can be built from a rigid rod, including anx3oscillator, are described.

ISSN:0002-9505    

DOI:10.1119/1.17966

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

We identifyallthe periodic orbits of the integrable swinging Atwood’s machine by calculating the rotation number of each orbit on its invariant tori in phase space, and also providing explicit formulas for the initial conditions needed to generate each orbit.

ISSN:0002-9505    

DOI:10.1119/1.17967

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

The reasons for identifying the contributions of women astronomers in introductory textbooks are discussed. The rates of inclusion of ten women astronomers are studied and analyzed. The evolution of inclusion over the past four decades is explored.

ISSN:0002-9505    

DOI:10.1119/1.17968

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP

摘要:

The pendulum, which can rotate in a vertical plane about a horizontal axis, consists of a tube with a pneumatically propelled internal slider which is driven periodically from one end of the tube to the other without changing the pendulum’s angular momentum. The resultant parametric oscillations can be observed in great detail, in both linear and nonlinear regimes, because of the multisecond time scales which characterize the system. It is shown that, in addition to the expected conditions for instability to occur, there is also an amplitude threshold caused by sliding friction in the pendulum’s bearings.

ISSN:0002-9505    

DOI:10.1119/1.17969

出版商:American Association of Physics Teachers    

年代:1995

数据来源: AIP