Rankers Physics

Dynamics of Rotational Motion: Practice Problem & Solution

A uniform pole of length l and mass m is pivoted on the ground with a frictionless hinge O. The pole is free to rotate without friction about an horizontal axis axis passing through O and normal to plane of the page. The pole makes an angle θ with the horizontal. The pole is released from rest in the position shown, then linear acceleration of the free end (P) of the pole just after its release would be Dynamics of Rotational Motion diagram: A uniform pole of length l and mass
(2g cosθ)/3
2g/3
g
(3g cosθ)/2

Solution Explained:

To solve this problem, we apply the core principles of Dynamics of Rotational Motion. Understanding the underlying formula is key to arriving at the correct answer below:

Torque of gravitational force mg about O is mgcosθ ×L/2

Torque = I × α

mgcosθ ×L/2 = (mL²/3) × α

α = (3gcosθ)/2

Leave a Reply

Your email address will not be published. Required fields are marked *

Similar Practice Questions

Explore conceptually related problems to test your knowledge.

1. A uniform circular disc of mass \(2\text{ kg}\) and radius \(100\text{ cm}\) (hinged at centre) is subjected to a constant torque of \(4\text{ Nm}\). If the disc was initially at rest, then its angular speed after \(4\text{ s}\) will be
2. A constant torque of 100 N m turns a wheel of moment of inertia \(300\text{ kg m}^2\) about an axis passing through its centre. Starting from rest, its angular velocity after 3 s is