A sphere of diameter $0.2\,m$ and mass $2\, kg$ is rolling on an inclined plane with velocity $ \upsilon =0.5\, m/s$. The kinetic energy of the sphere is:
The kinetic energy of sphere while rolling on an inclined plane is given by $ E_{K}= $ Translational kinetic energy $+$ Rotational kinetic energy $=\frac{1}{2} m v^{2}+\frac{1}{2} I \omega^{2}$ $E_{K}=\frac{1}{2} \times 2 \times(0.5)^{2}+\frac{1}{2} \times\frac{2}{3} \times 2 \times(0.1)^{2} \times\left(\frac{0.5}{0.1}\right)^{2}$ $=0.25+0.17=0.42 J$
The system of particles refers to the extended body which is considered a rigid body most of the time for simple or easy understanding. A rigid body is a body with a perfectly definite and unchangeable shape.
The distance between the pair of particles in such a body does not replace or alter. Rotational motion can be described as the motion of a rigid body originates in such a manner that all of its particles move in a circle about an axis with a common angular velocity.
The few common examples of rotational motion are the motion of the blade of a windmill and periodic motion.