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QJEEM24Ph8916: JEE Main 2024 Physics - Class 11 JEEM24Ph8916 Solution: A mass is suspended from a spring of negligible mass and the…

A mass mm is suspended from a spring of negligible mass and the system oscillates with a frequency f1f_1 . The frequency of oscillations if a mass 9 m9 \mathrm{~m} is suspended from the same spring is f2f_2 . The value of f1f2i\frac{f_1}{f_2} \mathrm{i} ________.

Step-by-Step Verified Solution

Let's start by considering the formula for the frequency of a mass on a spring (a simple harmonic oscillator):

f=12πkmf = \frac{1}{2\pi} \sqrt{\frac{k}{m}}

Where:

  • ff is the frequency of oscillation
  • kk is the spring constant
  • mm is the mass suspended from the spring

When the mass mm is suspended, the frequency f1f_1 is:

f1=12πkmf_1 = \frac{1}{2\pi} \sqrt{\frac{k}{m}}

When the mass 9m9m is suspended, the frequency f2f_2 is:

f2=12πk9mf_2 = \frac{1}{2\pi} \sqrt{\frac{k}{9m}}

We can simplify the square root by taking the 9 inside the root as 323^2 , which gives:

f2=12πk(32)mf_2 = \frac{1}{2\pi} \sqrt{\frac{k}{(3^2)m}}

f2=12π13kmf_2 = \frac{1}{2\pi} \frac{1}{3} \sqrt{\frac{k}{m}}

The ratio of f1f2\frac{f_1}{f_2} is therefore:

f1f2=12πkm12π13km\frac{f_1}{f_2} = \frac{\frac{1}{2\pi} \sqrt{\frac{k}{m}}}{\frac{1}{2\pi} \frac{1}{3} \sqrt{\frac{k}{m}}}

f1f2=113\frac{f_1}{f_2} = \frac{1}{\frac{1}{3}}

f1f2=3\frac{f_1}{f_2} = 3

So the value of f1f2\frac{f_1}{f_2} is 33 .

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