Elastic vs Inelastic

The differentiate between Elastic and Inelastic that Elastic is like let's say if I have two cars and I roll them at the same time there going to bounce off each so that's what Elastic is with to object bounce off each other and Inelastic is like two magnets you but them together they stay stick together so that what Inelastic is when to object or item sticks together.

Elastic Collision

I think that a train has momentum because it has a bigger mass and if it starts running / moving it will go at a faster speed then the skateboard. The skateboard doesn't because it has a small mass and depends on the person who using the skateboard and if the person gets off the skateboard the skateboard will keep going into it loses energy and then completely stops. 

Work vs. Power

Work is when you put in work to a object to make it move. Power is a rate where  work is done. When I run and dribowl the ball I put a lot of power and when I walk I but less power.