JEE MAINS || NEET || PURE ROLLING|| ROTATION MOTION скачать в хорошем качестве

JEE MAINS || NEET || PURE ROLLING|| ROTATION MOTION

Is friction necessary to remain a solid sphere to remain in a pure rolling? 🔵 Yes, friction is necessary for a solid sphere to remain in pure rolling motion, particularly when the sphere is accelerating, decelerating, or moving on an inclined surface. Static friction acts as the necessary torque to ensure the sphere rotates at the correct speed to match its linear translation, satisfying the no-slip condition \(v=R\omega \) (where \(v\) is linear velocity, \(R\) is radius, and \(\omega \) is angular velocity).  On an Inclined Plane: Friction is absolutely essential. Without friction, a sphere on an incline will slide down rather than roll, as gravity only acts to increase linear translation. Accelerating/Decelerating on Horizontal Surface: Static friction is required to adjust the rotational speed to match the changing linear speed, maintaining \(v=R\omega \). Constant Velocity on Horizontal Surface: If a sphere is already in a state of "pure rolling" at a constant speed, static friction may not be required to maintain that state. However, to initiate or maintain the condition against any change in velocity, friction is necessary. Work Done: During pure rolling, static friction does no work because the point of contact is instantaneously at rest (no relative displacement).  In summary, a rough surface is required to provide the necessary static friction to keep the sphere rolling without slipping.