Tip 1: How to find the center of gravity of the body

center of gravity of any body is considered to be a geometric point at which intersect all the force of gravity acting on the body in its every corner.Sometimes it does not coincide with any of the points of the body.
you need
  • - body
  • - thread
  • - line
  • - pencil
Guide
1
If the body's center of gravity is to be determined, homogeneous and has a simpleshape - rectangular, circular, spherical, cylindrical, square, and it has a center of symmetry, in this case the center of gravity coincides with the center of symmetry.
2
For a uniform rod center of gravity is in the middle, that is, in its geometric center.The same result is obtained for a uniform circular disc.Its center of gravity lies at the point of intersection of the circle diameter.Therefore, the center of gravity of the hoop will be in the center, away from the points of the hoop.Find the center of gravity of a homogeneous sphere - it is located in the geometric center of the sphere.The center of gravity of a homogeneous c
uboid will be at the intersection of its diagonals.
3
If the body has an arbitrary shape, if it is fragmented, for example, has a recess, to calculate the center of gravity is difficult.Understand where such a body is the point of intersection of all the forces of gravity acting on the figure when it is turning.Find this point easiest to empirically using free hanging manner on the filament body.
4
consistently attach the body to the thread for the different points.At equilibrium, the center of gravity of the body must lie on the line coinciding with the line of the thread, otherwise the force of gravity would lead body in motion.
5
Using the ruler and pencil draw a vertical line coinciding with the direction of the threads that were attached at various points.Depending on the complexity of the shape of the body will need to spend two or three lines.They must all intersect at one point.This point will be the center of gravity of the body, because the center of gravity shall be at the same time all of these lines.
6
determined using the method of hanging as the center of gravity of a plane figure, and more complex body, the shape of which can vary.For example, two bars connected by a hinge in the unfolded state have a center of gravity of the geometrical center, but in a bent - their center of gravity is outside of the bars.

Tip 2: How to determine the center of gravity

still in school physics classes, we first meet with this notion, as the center of gravity.Not an easy task, but well explained and understood.Not only the young physics need to know the definition of the center of gravity.And if you are faced with this task, it is necessary to resort to hints and reminders in order to upgrade your memory.
How to determine the center of gravity
Guide
1
Having studied the textbooks of physics, mechanics, dictionaries or encyclopedias, you stumble upon the definition of the center of gravity or how else is called the center of mass.

in different sciences slightly different definition, but are, in fact, is not lost.The center of gravity is always in the center of symmetry of the body.For a clearer concept of "the center of gravity (or another name for the center of mass) - a point that has always connected with a solid body.Through it passes the resultant force of gravity acting on the particle at any given body of his position. "
2
If the center of gravity of a rigid body - this is the point, then it must have the coordinates.

important to know to determine the coordinates x, y, z, i-of that part of the body and weight, denoted by the letter - p.
3
Consider the example of a problem.

Given two bodies of different masses m1 and m2, which are different weight force (as shown below).Writing the formula weight:

P1 = m1 * g, P2 = m2 * g;

center of gravity between two masses.And if the whole body hung in the point O, the value of the balance will come, that is, the items will no longer outweigh each other.
4
variety of geometric shapes have a physical and mathematical calculations on the center of gravity.To each its own approach and its own method.

Considering disc, it is specified that the center of gravity is within him, more precisely at the point of intersection of the diameters (as shown in TS - The intersection of the diameter).In the same way is the center of the box or a homogeneous sphere.
5
Presented drive and two bodies with the masses m1 and m2 - smooth and regular shape.It may be noted that the desired contact center of gravity is within these subjects.However, a nonhomogeneous mass bodies with irregular shape and the center can be located outside the subject.You feel for yourself what the task is becoming more difficult.
Sources:
  • center of gravity of the bodies
  • how to determine the center of gravity of the body

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