A $\backslash (150-\backslash$mathrm$\{$kg$\}\backslash )$ block is sliding down a smooth inclined plane, as shown in the figure. At the position indicated, the block has a velocity of $\backslash (3\backslash$mathrm$\{$~m$\}/\backslash$mathrm$\{$s$\}\backslash )$ along the plane, and the attached spring $($spring constant $\backslash (\backslash$mathrm$\{$k$\}=25\backslash$mathrm$\{$~N$\}/\backslash$mathrm$\{$m$\}\backslash ))$ is stretched by $0\mathrm{.}3$ m $.$ Using the principle of work and energy, calculate the velocity of the block after it has moved $1\mathrm{.}5$ m further down the plane.