How to determine the center of gravity of the ball and how to determine the center of gravity of the

1.The center of gravity of a perfectly symmetrical geometry is the center of mass of the geometry, and if it is a sphere, it is the center of the sphere, which is the center of mass.

For the formula, please refer to Peking University Press, General Course of College Physics, Mechanics, p105 page of the centroid vector expression.

2.The steps to find the center of gravity of asymmetrical geometry or uneven density geometry are as follows: after tying the object with a string, it will naturally sag, and there will be an imaginary straight line extending the string through the object, and then repeat this method twice after marking, and the intersection of the three straight lines is the center of gravity.

I forgot which physics book the center of gravity formula it was, or I forgot it in theoretical mechanics, I forgot to look for it myself, it's a system of equations, and I can't type in the formula.

Note that some specially shaped objects may have a center of gravity outside the object.

Regardless of whether the mass is uniform or uneven, as long as it is hung with a thread, the vertical extension of this line passes through the sphere, and after many times of this operation, the vertical extension of several such lines pass through the sphere and intersect at a certain point in the sphere, which is the center of gravity of the sphere. Homogeneous mass can be measured with a length measuring tool, while uneven mass can only be measured with this method.

If it is not a sphere, but an irregularly shaped object, it is possible that the center of gravity is not inside the object at all, but outside the object. It can also be measured according to the above method.

1.The center of a ball of uniform density is the center of mass of the geometry.

If it is a sphere, it is the center of the sphere, which is the center of mass.

2.The steps to find the center of gravity of asymmetrical geometry or uneven density geometry with the wide age test method are as follows: tie the object with a string and then hang down naturally, there will be an imaginary straight line extending the string through the object, and then repeat it twice after marking with this square key method, and the intersection of the three straight lines is the center of gravity.

If you have any details, please feel free to ask.

o( oIf mine is helpful to you, remember oh, thank you very much!)

A hollow sphere with uniform mass distribution, the center of gravity is in the positive **.

Below the knee, about 30 cm above the ground - waist. - There are several situations of dribbling: 1. Rapid dribbling between movements; 2. Dribble the ball between slow marches; 3. Dribbling when stationary (in place); 4. Dribbling from stationary to moving (fast start).

In the first case, the center of gravity should be high, which is conducive to fast running and sudden changes of direction, and the high center of gravity at this time should have a kind of drifting agility, so that the defender cannot determine the direction of your next movement. The second is the feeling of walking, which is generally in the backcourt, and in the absence of defenders, relaxing the dribble is conducive to physical recovery. The third situation is to dribble and wait for players to respond or dribble when blocking, at this time it is mainly to protect the ball, so you have to dribble sideways.

The center of gravity should be on the front foot, raise the hand to protect the ball, and lean forward slightly, so that you can quickly start to break through. In the fourth case, just like the start when we run 100 meters, from stationary to fast running, so the center of gravity should fall half a step in front of the body, so that we can gain an inertia when the body falls forward, which is conducive to our rapid start.

a. Not only the center of gravity on the object is affected by gravity, but all parts of the object are subject to gravity Therefore, a is false b. The center of gravity is the concentration point of gravity on the object, and it is not necessarily on the object, for example, the center of gravity of a uniform ring is outside the ring; Therefore, B error C, the center of gravity of the sphere is not necessarily on the center of the sphere, but also related to the mass distribution of the sphere; Therefore, c is wrong d, the position of the center of gravity of the object is related to the shape of the object and the mass distribution in the object

In junior high school, it was believed that gravity must be directed towards the center of the earth.

High school level: gravity points to the center of the earth, and a global object can be considered equal to gravity, at which point to the center of the earth.

For objects on the ground, the gravitational force is divided into the centripetal force and the gravitational force used by the earth to rotate. The centripetal force points to the earth's axis, so strictly speaking, gravity does not point to the center of the earth (deviates a little), but the heart force to tell the old man is very, very small, so the gravitational force mainly provides gravity, which is roughly considered to be the gravity of the socks to rise to the center of the earth.

Objects on the equator, gravitational force, gravity, and centripetal force have the same direction, and pointing to the earth's axis on the equator is pointing to the center of the earth;

Objects at the poles, do not need centripetal force, gravitational force all provides gravity, and at this time also points to the center of the earth.

In reality: your question should first be discussed as I mentioned above (as above in the textbook), but note that the textbook treats the earth as a mass point and treats it as a uniform positive sphere, and only when the centripetal force is ignored is that gravity points to the center of the sphere.

In real life, due to the shape and unevenness of the earth, gravity does not point to the center of the sphere, and gravity does not point to the center of the sphere. However, the gap with the theory is not too big, if it is not a precise scientific research, you can roughly judge the direction of power.

And you don't know how to ask me