MCQ
A block of mass $m$ is having two similar rubber ribbons attached to it as shown in the figure. The force constant of each rubber ribbon is $K$ and surface is frictionless. The block is displaced from mean position by $x\,cm$ and released. At the mean position the ribbons are underformed. Vibration period is


- A$2\pi \sqrt {\frac{{m(2k)}}{{{k^2}}}} $
- B$\frac{1}{{2\pi }}\sqrt {\frac{{m(2k)}}{{{k^2}}}} $
- ✓$2\pi \sqrt {\frac{m}{k}} $
- D$2\pi \sqrt {\frac{m}{k+k}} $


