---
title: "A uniform rod of mass \\( M_0 \\) and length \\( L \\) is free to rotate about a pivot at its left end and is released from rest when the rod is \\( 30^{\\circ} \\) below the horizontal, as shown in the figure. With respect to the pivot, the rod has rotational inertia \\( I_0 = \\dfrac{1}{3} M_0 L^2 \\). Which of the following expressions correctly represents the magnitude of the net torque exerted on the rod about the pivot at the moment the rod is released?"
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url: "https://nerd-notes.com/ubq/88432/"
date_modified: "2025-10-28T03:52:50+00:00"
---

# A uniform rod of mass \( M_0 \) and length \( L \) is free to rotate about a pivot at its left end and is released from rest when the rod is \( 30^{\circ} \) below the horizontal, as shown in the figure. With respect to the pivot, the rod has rotational inertia \( I_0 = \dfrac{1}{3} M_0 L^2 \). Which of the following expressions correctly represents the magnitude of the net torque exerted on the rod about the pivot at the moment the rod is released?

A uniform rod of mass \( M_0 \) and length \( L \) is free to rotate about a pivot at its left end and is released from rest when the rod is \( 30^{\circ} \) below the horizontal, as shown in the figure. With respect to the pivot, the rod has rotational inertia \( I_0 = \dfrac{1}{3} M_0 L^2 \). Which of the following expressions correctly represents the magnitude of the net torque exerted on the rod about the pivot at the moment the rod is released?

![Diagram](https://nerd-notes.com/wp-content/uploads/2025/04/rotationalpivot123ubq-1024x497.png)

- **A.** \( M_0 g \left( \dfrac{L}{2} \right) \sin(30^\circ) \)
- **B.** \( M_0 g \left( \dfrac{L}{2} \right) \sin(60^\circ) \)
- **C.** \( M_0 g L \sin(30^\circ) \)
- **D.** \( M_0 g L \sin(60^\circ) \)

*The answer key and step-by-step explanation are available to logged-in users at https://nerd-notes.com/ubq/88432/*