As the name implies.

All parts of an object are affected by gravity. From the effect, we can think that the gravity of each part is concentrated on one point, which is called the center of gravity of the object.

Center of gravity of triangle:

The center of gravity is the intersection of the median lines of three sides of a triangle.

Center of gravity of line segment

The center of gravity of the line segment is the midpoint of the line segment.

The center of gravity of a parallelogram is the intersection of its two diagonals.

Method of finding the center of gravity

A. Hanging method

It only applies to very thin objects. First find a thin rope, find a point on the object, hang it with a rope, and draw a gravity line after the object is stationary. Similarly, find a point to hang it. The intersection of two gravity lines is the center of gravity of the object.

B. Support methods

There is a point supporting the object, and its position is constantly changing. The more stable the position, the closer to the center of gravity.

Properties of triangle center of gravity

The center of gravity is the intersection of the median lines of three sides of a triangle.

1, and the ratio of the distance from the center of gravity to the vertex to the distance from the center of gravity to the midpoint of the opposite side is 2: 1.

2. Equal product:

The areas of the three triangles formed by the center of gravity and the three vertices of the triangle are equal.

3. The sum of squares of the distances from the center of gravity to the three vertices of the triangle is the smallest.

4. The vector sum from the center of gravity to the three vertices of the triangle is zero.

The focus of the work is to control the population.