How does the shape of the object affect gravity?

Types of mechanical forces¶

Radial force¶

Due to its mass, a body always moves along a straight path when no force is acting on it. A circular movement is only possible if a force keeps the body on the circular path, i.e. accelerates it continuously towards the center of the circle. This force is called radial force or centripetal force.

The law of force also applies to the amount of radial force. With the radial acceleration follows for the radial force :

If one is on a circular path as an observer, however, one perceives the corresponding counterforce ("centrifugal force"). For example, if you sit in a vehicle that is steering to the left, a force appears to be acting that accelerates your body to the right (apparent force). In reality, one tries to move straight ahead due to inertia and is only forced onto the circular path by the radial force acting towards the center of the circle.

Technically, the radial force is used in centrifuges, for example. Here, a mixture of substances to be separated, which are located in a test tube, for example, is set in a circular motion with high angular velocity and a small path radius. The substance mixture is separated according to its density proportions, the "heavier" substances move outwards due to their inertia and are thus deposited on the bottom of the rotating vessel. This stratification remains even after the centrifuge has been switched off, since ultimately nothing other than a sedimentation process has taken place - just a very fast one. The radial acceleration caused by the radial force can be achieved with centrifuges or ultracentrifuges - to times the acceleration due to gravity be.


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