Given data:
The net force in case I is F_net.
The net force in case II is F'_net=2F_net.
The distance traveled is d.
The work energy theorem is given by,

Here, KE is the kinetic energy, and W is the work done.
The work done in case I is,

The work done in case II is,

The ratio of kinetic energy will be,

Thus, the final kinetic energy is doubled.
Final Answer:
Its final kinetic energy is doubled.