Pöörlemisfääri

Pöörlemisfääri is an Estonian term that translates to "sphere of rotation" or "rotating sphere" in English. It refers to a geometric shape that is formed by rotating a two-dimensional circle around one of its diameters. The resulting three-dimensional object is a solid sphere.

The properties of a pöörlemisfääri are the same as those of a standard sphere. It is characterized by a single point at its center and a constant radius extending from this center to any point on its surface. The surface of a pöörlemisfääri is called a spherical surface, and it encloses a volume.

In mathematics and physics, the concept of a pöörlemisfääri is fundamental. It is used in various calculations, including determining volume, surface area, and moments of inertia. For example, the volume of a pöörlemisfääri with radius 'r' is given by the formula (4/3)πr³, and its surface area is 4πr².

The term might be used in contexts discussing rotational symmetry, where a sphere inherently possesses perfect rotational symmetry around any axis passing through its center. This means that no matter how you rotate a sphere around such an axis, it will always appear the same.

While "pöörlemisfääri" specifically denotes the sphere generated by rotation, in many practical applications, it is simply referred to as a "sfäär" (sphere) once the object is conceptualized as a complete three-dimensional entity. The term emphasizes its origin through a rotational process.