$(1)$ A II$-$k bbock, altached to the lawer end of spring whose upper end is fiked vibrates with a period of $7\mathrm{.}2s$ knowing that the constant of spring $K$ is inversely proportiond to its both $($e$.8,$ if you cut a $10N$ m spring in half the remaining two spring each have a spring constont of $20\frac{N}{m}\frac{?}{?}.$ find the period of a $7kg$ block which is attachad to the center of the some spring if the Lipper and bwes ande of spring are fixed.