Method for measuring gravitational acceleration by using conical pendulum

Abstract

The invention provides a method for measuring gravitational acceleration by using a conical pendulum and relates to the field of physical parameter measurement. The method is novel for measuring the gravitational acceleration. According to the technical scheme, the length of a cycloid of a simple pendulum is L, the radius of a pendulum ball is r, and a semi-hard plastic sheet with the length a is fixed to the other side opposite to the cycloid in the diameter direction, where the cycloid is located, of the pendulum ball. The pendulum ball of the simple pendulum is driven by a rotating shaft to do the circular motion, the included angle theta of the cycloid and the vertical direction and a swing cycle T of the pendulum ball are measured, and thus the gravitational acceleration g=(2pi/T)2*L'cos theta, wherein pi=3.1415926. The method for measuring the gravitational acceleration by using the conical pendulum has the advantages that the novel method for measuring the gravitational acceleration is proposed, students are guided to correctly understand errors; compared with the mode that the inclination angle amplitude of the simple pendulum is gradually reduced due to air resistance, driving of a motor is adopted in the method, and stable operation at the constant speed can be ensured; the cyclic formula of the simple pendulum is an approximation, the inclination angle is required to be within five degrees, and the requirement is avoided in the method.

Description

technical field [0001] The invention relates to the field of measurement of physical parameters, especially the measurement of gravitational acceleration. Background technique [0002] In university physics laboratories, simple pendulums and compound pendulums are commonly used to measure gravitational acceleration. The pendulum ball of a simple pendulum is only controlled by the suspension point and the cycloid. The cycloid is soft. When doing the simple pendulum experiment, if it is not done well, it will be made into a conical pendulum in extreme cases. The conical pendulum is equivalent to A simple pendulum with a shorter pendulum length leads to a shorter measurement period, which leads to a larger measured value of the acceleration of gravity; of course, most of the time it will not reach the extreme of the conical pendulum, usually a cone is superimposed in the single pendulum motion pendulum motion; worst of all, the components of the conical pendulum cannot be esti...

AI Technical Summary

Problems solved by technology

The pendulum ball of a simple pendulum is only controlled by the suspension point and the cycloid. The cycloid is soft. When doing the simple pendulum experiment, if it is not done well, it will be made into a conical pendulum in extreme cases. The conical pendulum is equivalent to A simple pendulum with a shorter pendulum length leads to a shorter measurement period, which leads to a larger measured value of the acceleration of gravity; of course, most of the time it will not reach the extreme of the conical pendulum, usually a cone is superimposed in the single pendulum motion pendulum motion; worst of all is the inability to estimate the components of the conical pendulum

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