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Oscillations

Question
CBSEENPH11026427

A mass M is suspended from a spring of negligible mass. The spring is pulled a little and then released so that the mass executes simple harmonic oscillations with a time period T. If the mass is increased by m, then the time period becomes 54 T. The ratio of mM is

  • 9/16

  • 5/4

  • 25/16

  • 4/5

Solution

A.

9/16

The time period of oscillation is 

          T = 2π MK

M = mass attached to spring

and       T1 = 2π M + mK

⇒          T1T = M + mM

⇒           54 = 1 + mM12                    T1 = 54T

⇒             mM = 2516 - 1

⇒               mM = 916