Final answer:
The kinetic energy of the object after hitting the wall remains the same at 2 J.
Step-by-step explanation:
The kinetic energy of an object in motion is given by the equation:
KE = (1/2)mv^2
where KE is the kinetic energy, m is the mass of the object, and v is the velocity (speed) of the object.
In this case, the object has a mass of 1 kg and a kinetic energy of 2 J. When it hits a wall and comes back with its original speed, its kinetic energy remains the same.
Therefore, the kinetic energy of the object after hitting the wall is still 2 J.