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Revista Brasileira de Ensino de Física

Print version ISSN 1806-1117On-line version ISSN 1806-9126

Abstract

REIS, T.O.; ZIEMATH, E.C.; OLIVEIRA, G.S.  and  LEITE, F.L.. Construction of a simple balance for determination of the surface tension of liquids. Rev. Bras. Ensino Fís. [online]. 2015, vol.37, n.1, 1503.  Epub Mar 12, 2015. ISSN 1806-1117.  http://dx.doi.org/10.1590/S1806-11173711658.

In the present work, it is suggested the construction of a balance using low-cost materials in order to determine surface tension of liquids. The reliability of the measurements was confirmed by comparing these results with those reported in the literature using capillary rise method for simple liquids. In the proposed method, the systematic errors from the obtained results obtained with this device are reduced considerably. The principle of the device’s operation consists of measuring the force required to remove/detach a glass slide partially immersed in a liquid. The values of surface tension are calculated based on concepts of moment of a force (torque) and considering intermolecular interactions between glass and liquid surface.

Keywords : surface tension; intermolecular forces.

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