19. which type of collision is hitting a baseball with a bat? * 2 points elastic collision inelastic collision neither both

Easy. The answer to your question is Inelastic Collision. 

Why? elastic collision, is a collision in which kinetic energy is not conserved due to the action of internal friction.

Where as, elastic collision is conserved were it maintains (a quantity such as energy or mass) at a constant overall total.

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