Short Title

Measuring Newton's Constant of Universal Gravitation


gravity, gravitation, experiment, newton, constant, cavendish, torsion balance, big g

Subject Area

Physics, Laboratory

Type of Submission



Newton’s Constant of Universal Gravitation is used in the calculation of gravitational attraction between any two or more objects. In this experiment, we use a rotating torsional pendulum, different sized masses, and an optical lever to determine the value of this constant. After accounting for additional forces acting on our masses and various sources of error, we determined our most precise measurement for the constant of universal gravitation to be 6.4110-11 ± 5.1610-13 m3kg−1s−2. This measurement, given the NIST CODATA value of 6.6740810-11 m3kg−1s−2, was 5.1 times our uncertainty.