Torsional scales - a physical device designed to measure small forces or torques . They were invented by Charles Koulon in 1777 (according to other data, in 1784) to study the interaction of point electric charges and magnetic poles. [1] In the simplest version, the device consists of a vertical thread on which a lightly balanced lever is suspended.
Content
Principle of action
Under the action of the measured forces, the lever begins to turn in the horizontal plane until these forces are balanced by the elastic forces of the twisted thread. The angle of rotation of the lever you can judge the torque measurable forces since where - thread length, - shear modulus of the yarn material, - total moment of inertia of the lever and the thread.
The sensitivity of the balance increases with increasing length of the thread and with decreasing shear modulus of its material.
Scientific application
In 1785, with the help of torsional weights, the law of interaction of two stationary point charges, the Coulomb law, was experimentally discovered. [2]
Also in 1797 - 1798, the torsion balance design was used by G. Cavendish to measure the gravitational constant and average density of the Earth. [3]
See also
- Torsion pendulum
Notes
- ↑ Torsional scales - an article from the Great Soviet Encyclopedia .
- ↑ Torsional scales - an article from the Great Soviet Encyclopedia .
- ↑ For details, see Cavendish Experiment
Literature
- Physical Encyclopedic Dictionary / Ch. ed. A. M. Prokhorov. Ed. count D. M. Alekseev, A. M. Bonch-Bruyevich, A. S. Borovik, and others. - Moscow: Sov. encyclopedia, 1983. - p. 333. - 982 p. - 100 000 copies
Links
- Torsional scales - an article from the Great Soviet Encyclopedia .