The Definition of Kinetic Energy is given by, we have:
[tex]E_{c}= \frac{mv^2}{2} [/tex]
Enteriing the unknowns, we have:
[tex]E_{c}= \frac{mv^2}{2} \\ 3.13*10^5*J= \frac{290*kg*v^2}{2} \\ v^2= \frac{3.13*10^5*J}{145*kg} \\ v=46.461* \sqrt{ \frac{J}{Kg} } \\ v=46.461* \sqrt{ \frac{N*m}{Kg} } \\ v=46.461* \sqrt{ \frac{ \frac{Kg*m}{s^2} *m}{Kg} } \\ \boxed {v=46.461*m/s}[/tex]
Obs: approximate results.
If you notice any mistake in my english, please let me know, because i am not native.