Answer:
v = 24.49[m/s]
Explanation:
We must remember that kinetic energy can be calculated by means of a mathematical expression, which relates kinetic energy to mass and velocity
[tex]E_{kin}=\frac{1}{2}*m*v^{2} \\[/tex]
where:
Ekin = kinetic energy = 12000 [J]
m = mass = 40 [kg]
v = velocity [m/s]
[tex]12000=\frac{1}{2} *40*v^{2}\\24000=40*v^{2}\\600=v^{2}\\v=\sqrt{600}\\v=24.49[m/s][/tex]