Question

A copper sphere attached to the bottom of a vertical spring is oscillating with time period $10s$ . If the copper sphere is immersed in a fluid (assume the viscosity of the fluid is negligible) of specific gravity $\frac{1}{4}$ of that of the copper, then time period of the oscillation is:

• A. $5s$
• B. $10s$
• C. $2.5s$
• D. $20s$

Answer 1

Answer: (B)

$10s$

Given: Time Period, $T=10s$

We know that, $T=2\pi \sqrt{\frac{m}{k}}$

When the system is immersed in the liquid with specific gravity one fourth of that of copper and the liquid is non viscous, the time period would not change because there is no change in $m$ and $k$.