1. Identify the effective spring constant

The block is attached to two identical springs of spring constant $K=2\,\text{N m}^{-1}$.

When the block is displaced horizontally by $x$, each spring contributes a restoring force toward equilibrium. So the net restoring force is

$F=-(K+K)x=-2Kx$

Hence, the effective spring constant is

$k_{\text{eff}}=2K=2\times 2=4\,\text{N m}^{-1}$

2. Write the angular frequency

For SHM,

$\omega=\sqrt{\frac{k_{\text{eff}}}{M}}$

Given mass,

$M=490\,\text{g}=0.49\,\text{kg}$

Thus,

$\omega=\sqrt{\frac{4}{0.49}}$

$\omega=\sqrt{\frac{400}{49}}=\frac{20}{7}\,\text{rad s}^{-1}$

3. Find the time period

$T=\frac{2\pi}{\omega}$

So,

$T=\frac{2\pi}{20/7}=\frac{14\pi}{20}=\frac{7\pi}{10}\,\text{s}$

4. Find number of complete oscillations in $14\pi$ seconds

Number of oscillations,

$n=\frac{t}{T}$

Given $t=14\pi$ s,

$n=\frac{14\pi}{7\pi/10}=14\pi\times \frac{10}{7\pi}=20$

5. Final answer

The number of complete oscillations is

$\boxed{20}$