摘要:

The term hydrostatic paradox is likely to suggest the classical experiment of “Pascal's vases.” In a demonstration with this apparatus the observer's attention is centered upon the vertical direction, specifically the common vertical depth of liquid in the different branches of the container, with their varying cross sections and volumes. But the term properly has a broader connotation. Fully as striking is the hydrostatic paradox seen in the fact that the horizontal thrust of the water against a dam is independent of the volume of water impounded, and dependent only on its depth at the barrier. To differentiate sharply between these two aspects of hydrostatic paradox, the terms “Phase I” and “Phase II” are proffered. The two aspects are discussed in the paper. A simple projection cell is described for demonstrating Phase II in a direct manner, corresponding to the demonstration of Phase I with Pascal's vases. Considered also is the involvement of hydrostatic paradox with Archimedes' principle, and in capillary tubes.

ISSN:0002-9505    

DOI:10.1119/1.1933913

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

摘要:

Two additional fifteenth-century paintings of note in which spectacles are clearly portrayed are here reproduced and commented upon.

ISSN:0002-9505    

DOI:10.1119/1.1933914

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

摘要:

This paper describes an experiment for the measurement of resistance in absolute units, based on the bridge method developed by H. L. Curtis and R. W. Curtis [Bur. Standards J. Research12, 665–734 (1934)]. The main modifications introduced in the work were the use of a mica instead of an air capacitor, a simplified method of measuring its capacitance in terms of resistance, and the use of the Anderson bridge in place of the Maxwell-Wien bridge for the determination of a relation between capacitance and inductance. A simple formula accurate to 0.4 percent was derived for the evaluation of the inductance of the single layer solenoid used in this work.

ISSN:0002-9505    

DOI:10.1119/1.1933915

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933917

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933919

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933920

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933922

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933925

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP

ISSN:0002-9505    

DOI:10.1119/1.1933926

出版商:American Association of Physics Teachers    

年代:1955

数据来源: AIP