Question:
A bob of mass m attached to an inextensible string of length l is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed $\omega \,rad/s$ about the vertical support. About the point of suspension
A bob of mass m attached to an inextensible string of length l is suspended from a vertical support. The bob rotates in a horizontal circle with an angular speed $\omega \,rad/s$ about the vertical support. About the point of suspension
Updated On: Jul 8, 2024
- Angular momentum is conserved
- Angular momentum changes in magnitude but not in direction
- Angular momentum changes in direction but not in magnitude
- Angular momentum changes both in direction and magnitude
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The Correct Option is C
Solution and Explanation
$\tau=mg \times l \,\sin \,\theta $ (Direction parallel to plane of rotation of particle)
as $\tau$ is perpendicular to $\vec{L}$, direction of $L$ changes but magnitude remains same
as $\tau$ is perpendicular to $\vec{L}$, direction of $L$ changes but magnitude remains same
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Concepts Used:
System of Particles and Rotational Motion
- 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.