Question

A heavy brass sphere is hung from a light spring and is set in vertical small oscillation with a period $T$. The sphere is now immersed in a non-viscous liquid with a density $1/10th$ the density of the sphere. If the system is now set in vertical S.H.M ., its period will be :

• A. $\left(9/10\right)T$
• B. ${\left(9/10\right)}^{2}T$
• C. $\left(10/9\right)T$
• D. $T$

Answer 1

The correct option is D $T$

The time period this mass and spring system depends upon the mass $\left(m\right)$ of the sphere and spring constant $\left(k\right)$ of the spring. Since neither of them changes when it is immersed in the liquid. So the time period of the system will remain unchanged.
note: there is a decrease in the weight of the sphere but not in the mass.