College Physics ›› 2021, Vol. 40 ›› Issue (3): 56-61.doi: 10.16854 /j.cnki.1000-0712.200215

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Improvement of the experiment using a single pendulum to determine gravitational acceleration

LIU Yu-qi1,TAN Yu-sha1,WEI Xian-tao2,ZHANG Quan2,ZHAO Wei2,ZHU Ling2   

  1. 1. School of Earth and Space Sciences,University of Science and Technology of China,Hefei,Anhui 230026,China; 2. School of Physical Sciences,University of Science and Technology of China,Hefei,Anhui 230026,China
  • Received:2020-05-28 Revised:2020-07-24 Online:2021-03-20 Published:2021-03-23

Abstract: In the experiment of measuring the gravity acceleration by a single pendulum,it is difficult to determine

the pendulum length very accurately. Under the better measurement conditions,the measurement accuracy

could generally reach the order of millimeter,and the relative error of the measured gravity acceleration is generally

about 1%. In order to solve this problem,in this paper the measuring precision was improved to 0.02mm by using

avernier caliper connected with a cycloid to accurately measure the change of pendulum length instead of directly

measuring the pendulum length. At the same time,the swing period of the pendulum ball is measured by a photoelectric

gate,and the different cycloid material and diameter are compared and analyzed.The measurement error of

acceleration is controlled within 0.1%.

Key words: single pendulum, gravity acceleration, cycloid, change of pendulum length, angular amplitude