The original experiment was proposed by John Michell (1724-1793), who first constructed a torsion balance apparatus. Gravity would pull the freely suspended rod and small spheres toward the more massive balls. In this experiment, we attempt to experimentally mea- After a little algebra, this is con-verted into G= 6:74 10 11 m3 kg 1 s 2, remarkably close to the current accepted value of G= 6:673 10 11 m3 kg 1 s 2 [2]. Cavendish Experiment. His data give a value of ˆ= 5:448 g/cm3. In actuality, Cavendish's only goal was to measure the density of the Earth; he called it 'weighing the world'. 00008 . Pages 15 This preview shows page 10 - 14 out of 15 pages. by Ron Kurtus (20 February 2015) By examining the relationships between the various factors in the Cavendish Experiment, you can derive the equation for the Universal Gravitational Constant, G.. The value I used for my calculations is ω= 0. Finding The Value of G The Cavendish Experiment Newton knew that their had to. The wire acts as a torsion pendulum, which can rotate in a horizontal arc. As mentioned before Cavendish’s experiment was done by having a torsion balance hung from a system of pulleys, at each end of the torsion bar there was a 0.72kg lead ball. The lab instructions mention a program from Vernier called Graphical Analysis. Derivation of Gravitational Constant from Cavendish Experiment. The Cavendish experiment was the first to allow a calculation of the gravitational constant (G) by measuring the force of gravity between two masses in a laboratory framework. The value obtained for T is shown in Table 3. III. School University of Texas, Dallas; Course Title PHYS 382; Uploaded By dihar11700. 01233 ± 0. This experiment was the first to measure the force of gravity between masses in the laboratory and the first to yield accurate values for the gravitational constant. Repeat Henry Cavendish’s Experiment It is not unusual to find books that state erroneously that Cavendish's purpose was determining the gravitational constant (G). Setup of Cavendish Experiment . They also use the data to determine the Law of Gravity as Newton did. Cavendish's experiment was so well constructed that it was a hundred years before more accurate measurements were made. This lab guides student through a process similar to what was done with Henry Cavendish's experimental results to determine G and the mass of the Earth. A graphing calculator or Excel also can be used. The Cavendish experiment uses two small but equal masses at the ends of a light horizontal bar that is suspended on a wire and free to rotate in a horizontal plane. The experiment uses a torsion balance device to measure the movement of smaller lead balls toward the larger balls. The Cavendish experiment consists of a wooden rod horizontally suspended from a wire, with two small lead balls attached to each end. The calculation of its value was based on the results of an experiment to determine 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. Form another system of pulleys there was another torsion balance with a 158kg balls hanging from each end of the bar. The Cavendish Experiment was invented/founded in 1797-1798 by a British scientist by the name Henry Cavendish. Cavendish did not measure Gas we know it, but instead sought to measure the density of the Earth. Finding the value of g the cavendish experiment. Two more massive lead balls were placed near the smaller balls.