cavendish torsion bar experiment

Experiment measuring the force of gravity (1797-1798) Cavendish's diagram of his torsion pendulum, seen from above. The pendulum consists of two small spherical lead weights (h, h) hanging from a 6-foot horizontal wooden beam supported in the center by a fine torsion wire. The beam is protected from air currents inside a wooden box (A, A, A, A).

figure 1. the twin dumbbells of the Cavendish experiment. The Cavendish apparatus we currently use is built by PASCO. 1 The quartz fiber and smaller dumbbell are enclosed in a metal case with glass window for protection. A plan view of the spheres and dimensions are given in figure 2.

Cavendish experiment, measurement of the force of gravitational attraction between pairs of lead spheres, which allows the calculation of the value of the gravitational constant, G.In Newton's law of universal gravitation, the attractive force between two objects (F) is equal to G times the product of their masses (m 1 m 2) divided by the square of the distance between them (r 2); that is, F ...

The experiment was performed in 179798 by the English scientist Henry Cavendish. He followed a method prescribed and used apparatus built by his countryman, ...

Cavendish demonstrated this using a torsion balance, a horizontally suspended wooden rod with a small lead sphere at each end. Two large lead spheres were fixed in place, 9 inches from each of the ...

performed experiments with a torsion balance, measuring the gravitational attraction between relatively small objects in the laboratory. The value he determined for G allowed the mass and density of the Earth to be deter-mined. Cavendish's experiment was so well constructed that it was a hun-dred years before more accurate measurements were made.

the density of the earth performed by Henry Cavendish, and published in 1798.1 The purpose of this experiment is to perform a modern version of the Cavendish experiment, determine the gravitational constant, G, and compare it to its accepted value. 2 Theory The primary apparatus used to perform this experiment is the torsion balance which is

forces produced in this experiment are very weak, it is nonetheless sensitive enough to measure them and give an approximate value of G. I. BACKGROUND The computerized Cavendish balance is a torsion pen-dulum whose angular motion is recorded on a computer. The torsion pendulum is suspended by a tungsten wire

THE CAVENDISH EXPERIMENT Physics 258/259 A sensitive torsion balance is used to measure the Newtonian gravitational constant G. The equations of motion of the torsion balance are solved in terms of the experimentally determined parameters, from which G is determined in two different limiting cases. I. INTRODUCTION

The Cavendish apparatus consists of a light horizontal rod suspended by a thin metal ribbon. Attached to each end of the rod is a lead ball of mass m, as shown in Fig. 1(a). If the rod is twisted from its equilibrium position, a torque due to the ribbon acts to return the rod to equilibrium. In order to minimize disturbances due to air currents ...