Elastic Collisions: Can Objects Move Off Together?

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In elastic collisions, both momentum and kinetic energy are conserved, meaning that the objects rebound off each other without any loss of energy. When two objects move off together after a collision, as in the case of a bullet embedding in a pendulum, kinetic energy is not conserved, indicating that the collision is inelastic. The rearrangement of the conservation equations confirms that such a scenario cannot be elastic. Therefore, if objects move off together post-collision, it is indeed an inelastic collision. This clarification reinforces the fundamental principles of collision types in physics.
Shark 774
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Hi guys, just wanted to clear a few things up for myself..

By rearranging the conservation of momentum and conservation of energy equations I think I've shown that a collision that involves the colliding objects moving off together after the collision (like a bullet getting stuck in a pendulum) cannot be elastic. Is this correct?

Thanks.
 
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Yes, that's correct.
 

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