I was wondering if there is a possibility where in inelastic collision the final kinetic energy is not less than the initial kinetic energy.
2 Answers
The kinetic energy of the center of masses of the two colliding bodies may increase if their internal structure changes, i.e. if at least one of the bodies were in an excited state, and the conservation laws of energy and momentum allow the exceeding energy to transform into kinetic energy.
It depends. If a projectile is scattered elastically from a target, it does not change the target state. If the state changes, the projectile may loose or gain energy. For example, if you scatter from an atom in the ground state, only excitations of atom are possible; they need energy for that. But if you scatter from an excites atomic state, the final atom can be found in a lower energy state, so the projectile gains energy.