Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JIPMER 2017
Exam
JIPMER
Year
2017
Subject
Physics
Chapter
Work, Power and Energy

JIPMER 2017 · Physics · Work, Power and Energy

A particle of mass m is executing oscillation about the origin on X...

A particle of mass mm is executing oscillation about the origin on XX-axis. Its potential energy is V(x)=K∣x∣3V(x)=K|x|^3. Where KK is a positive constant. If the amplitude of oscillation is aa, then its time period TT is proportional to

Options

  1. A1/a1 / \sqrt{a}
  2. Ba
  3. Ca\sqrt{a}
  4. Da3/2a^{3 / 2}

Correct answer

A. 1/a1 / \sqrt{a}

Step-by-step solution

Given, V=kx3V=k x^3 Total energy (E)=(E)= Maximum potential energy =ka3=k a^3 From conservation of energy 12m(dxdt)2+kx2=ka3⇒12m(dxdt)2=k(a3−x3)⇒dxdt=2km(a3−x3)dxa3−x3=2kmdt\begin{aligned} \frac{1}{2} m\left(\frac{d x}{d t}\right)^2+k x^2 & =k a^3 \\ \Rightarrow \frac{1}{2} m\left(\frac{d x}{d t}\right)^2 & =k\left(a^3-x^3\right) \\ \Rightarrow \frac{d x}{d t} & =\sqrt{\frac{2 k}{m}\left(a^3-x^3\right)} \\ \frac{d x}{\sqrt{a^3-x^3}} & =\sqrt{\frac{2 k}{m}} d t\end{aligned} or Integrating ∫0adxa3−x3=2km∫0T/4dtor∫0adxa3−x3=2kmT4\int_0^a \frac{d x}{\sqrt{a^3-x^3}}=\sqrt{\frac{2 k}{m}} \int_0^{T / 4} d t or \int_0^a \frac{d x}{\sqrt{a^3-x^3}}=\sqrt{\frac{2 k}{m}} \frac{T}{4} Let x=asin⁡θ⇒dx=acos⁡θdθ∴∫0π/2acos⁡θdθa3−(asin⁡θ)3=2kmT4x=a \sin \theta \Rightarrow d x=a \cos \theta d \theta \therefore \int_0^{\pi / 2} \frac{a \cos \theta d \theta}{\sqrt{a^3-(a \sin \theta)^3}}=\sqrt{\frac{2 k}{m}} \frac{T}{4}
Practice Work, Power and Energy on Quantrex Academy →

More from Work, Power and Energy

All Work, Power and Energy questions Full Work, Power and Energy list All JIPMER PYQs