When a body of mass 1 kg is suspended from a certain light spring hanging vertically, its length increases by 5cm. Now by suspending 2.0 kg block to the spring  if the block is pulled through 10 cm and released, the maximum velocity of it in  $m{s}^{-1}$  is $(\mathrm{g}=10{\mathrm{ms}}^{-2})$