A ball of mass $1\mathrm{ }\mathrm{k}\mathrm{g}$ moving with a velocity of $0.4\mathrm{ }\mathrm{m} {\mathrm{s}}^{-1}$ collides with another stationary ball. After the collision, the first ball moves with a velocity of $0.3\mathrm{ }\mathrm{m} {\mathrm{s}}^{-1}$ in a direction making an angle of ${90}^{\mathrm{o}}$ with its initial direction. The momentum of the second ball after the collision will be (in $\mathrm{kg} \mathrm{m} {\mathrm{s}}^{-1}$)