Book started to loose contact with shelf when maximum acceleration $a$ of shelf is such that,
$a_{\max } \geq g$
$\Rightarrow \quad \omega^2 A \geq g$
$\Rightarrow \quad \omega^2=\frac{g}{A}$.
So, frequency of oscillations is
$f=\frac{\omega}{2 \pi}=\frac{1}{2 \pi} \sqrt{\frac{g}{A}}$
$\Rightarrow \quad f=\frac{1}{2 \pi} \cdot \sqrt{2.5 \times 10^{-2}}=\frac{2 \times 10}{2 \pi}$
$\Rightarrow \quad f \approx 3.18 \,Hz$
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
$\mathrm{MSR}=8.45 \mathrm{~cm}, \mathrm{VC}=26$
For mark on paper seen through slab
$\mathrm{MSR}=7.12 \mathrm{~cm}, \mathrm{VC}=41$
For powder particle on the top surface of the glass slab
$\mathrm{MSR}=4.05 \mathrm{~cm}, \mathrm{VC}=1$
$(\mathrm{MSR}=$ Main Scale Reading, $\mathrm{VC}=$ Vernier Coincidence)
Refractive index of the glass slab is: