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Grade 12th passMechanics

An elastic string of length l supports a heavy particle of mass m and system is in equilibrium with elongation produced being e. the particle is now pulled down below the equilibrium position through a distance d and released. The angular frequency and maximum amplitude of SHM is

Profile image of ramani
8 Years agoGrade 12th pass
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1 Answer

Profile image of Rituraj Tiwari
5 Years ago

To tackle this problem, we need to analyze the situation using the principles of simple harmonic motion (SHM) and the properties of elastic materials. When we pull the particle down and release it, it begins to oscillate around the equilibrium position. Let's break down the concepts involved in determining both the angular frequency and the maximum amplitude of the SHM.

Understanding the System

The elastic string experiences an elongation due to the weight of the mass m when it is at rest. This elongation, denoted as e, results from the gravitational force acting on the mass. According to Hooke's law, the force exerted by an elastic material is proportional to its extension. In this case, we can express the force equilibrium for the mass at equilibrium as:

  • Weight of the mass: F_gravity = mg
  • Restoring force of the elastic string: F_spring = k \cdot e

Here, k represents the spring constant of the string. At equilibrium, these two forces balance out:

mg = k \cdot e

Angular Frequency of SHM

When you pull the mass down a distance d and release it, the system will start oscillating. The angular frequency (ω) of the oscillation can be derived from the spring constant and the mass using the formula:

ω = √(k/m)

To find k, we can rearrange the equilibrium equation:

k = mg/e

Substituting this expression for k into the angular frequency formula gives us:

ω = √(mg/(me)) = √(g/e)

Determining Maximum Amplitude

The maximum amplitude of the oscillation in SHM is simply the distance d that you pulled the particle down from its equilibrium position. When the particle is released, it will oscillate back and forth around the equilibrium position with this amplitude. Therefore:

A = d

Summary

To summarize, when the particle is pulled and released, it undergoes SHM characterized by:

  • Angular frequency: ω = √(g/e)
  • Maximum amplitude: A = d

This provides a comprehensive understanding of the motion of the particle in the elastic system. If you have further questions about the mechanics involved or related concepts, feel free to ask!