Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
A uniform cylinder of length L and mass M having cross-sectional area A is suspended, with its length vertical from a fixed point by a massless spring such that it is half-submerged in a liquid of density ρ at the equilibrium position. When the cylinder is given a small downward push and released it starts oscillating vertically with a small amplitude. If the force constant of the spring is k, the frequency of oscillation of the cylinder is

PhysicsOscillationsJEE Main
Options:
  • A 12π(k-AρgM)1/2
  • B 12πk+AρgM1/2
  • C 12π(k+ρgL2M)1/2
  • D 12π(k+AρgAρg)1/2
Solution:
2475 Upvotes Verified Answer
The correct answer is: 12πk+AρgM1/2
When cylinder is displaced by an amount x from its meanposition, spring force and upthrust both will increase. Hence,
Net restoring force = extra spring force + extra upthrust  

Or   F = - kx + Ax ρ g
 
Or a = - k + ρ Ag M x

Now,  f = 1 2 π a x

          = 1 2 π k + ρ Ag M

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.