The velocity of a particle executing SHM varies with displacement ($x$) as $4v^2=50–x^2$. The time period of oscillations is $\frac{x}{7} \mathrm{s}$. The value of $x$ is ______.

[Take $\pi =\frac{22}{7}$]

In the figure given below, a block of mass $M=490 \mathrm{g}$ placed on a frictionless table is connected with two springs having same spring constant ($K=2 \mathrm{N} {\mathrm{m}}^{-1}$). If the block is horizontally displaced through $X$ $\mathrm{m}$ then the number of complete oscillations it will make in $14\pi$ seconds will be ______.