According to 3rd equation of kinematics
[tex]\boxed{\sf v^2-u^2=2as}[/tex]
[tex]\sf\longmapsto v^2=2as+u^2[/tex]
[tex]\sf\longmapsto v^2=2(6.5)(150)+(0)^2[/tex]
[tex]\sf\longmapsto v^2=13(450)[/tex]
[tex]\sf\longmapsto v^2=5850[/tex]
[tex]\sf\longmapsto v=\sqrt{5850}[/tex]
[tex]\sf\longmapsto v=76.4m/s[/tex]