In the arrangement shown in figure  ${\text{m}}_{\text{A}}{\text{=4.0\hspace{0.17em}kg\hspace{0.17em}and\hspace{0.17em}m}}_{\text{B}}\text{=1.0\hspace{0.17em}kg}$. The system is released from rest and block B is found to have a speed 0.3 m/s after it has descended through a distance of 1m. Then the coefficient of friction between the block and the table is $\mathrm{x}$. Then find $9\mathrm{x}$ [Neglect friction elsewhere. (Take ${\text{g = 10\hspace{0.17em}m/s}}^2$ ).]