The length of a seconds pendulum at a height $h=2R$ from earth surface will be:

(Given: $R=$ Radius of earth and acceleration due to gravity at the surface of earth $g={\pi }^2 \mathrm{m} {\mathrm{s}}^{-2}$)

As per given figures, two springs of spring constants $K$ and $2 \mathrm{K}$ are connected to mass $\mathrm{m}$. If the period of oscillation in figure (a) is $3 \mathrm{s}$, then the period of oscillation in figure (b) will be $\sqrt{x} \mathrm{s}$. The value of $x$ is _____ .

A block of mass $2 \mathrm{kg}$ is attached with two identical springs of spring constant $20 \mathrm{N} {\mathrm{m}}^{-1}$ each. The block is placed on a frictionless surface and the ends of the springs are attached to rigid supports (see figure). When the mass is displaced from its equilibrium position, it executes a simple harmonic motion. The time period of oscillation is $\frac{\pi }{\sqrt{X}}$ in SI unit. The value of $X$ is______.