A view of the teaching of ”Center of Gravity”

「重心」の指導における一考察

A view of the teaching of ”Center of Gravity”

Creators Domen Haruo

As a body was cut into two parts with a plane at its center of gravity, are two separated masses thus obtained always equal to each other? Not only students but also school teachers have sometimes misunderstood as those are the same of the weight on all occasions. In this report, the present author gives a simple demonstration of the above-mentioned problem so that two masses are not always equal, rather not in general. For example, when a triangle is divided into two parts A and B along the line parallel to one side at the center of gravity, the part A is as a triangle and another part B trapezoid （a quadrangle）, and the ratio of the area of A to that of B is 4/5, namely the area of the top part (A) is always smaller than that of the bottom (B) so far as such the cutting parallel to the base.

[ISSN]0286-0597

[NCID]AN00240238