My daughter asked an insightful question.

"Daddy, why does the pitcher look so weird before he throws the ball?"

My reply. "What do you mean he looks weird?"

Her response. "He lifts his leg in the air and he has his hand behind his leg before he throws."

Lightbulb. "Ahhh, I get it, you are talking about his windup".

I grabbed a soft ball (soft ball, not a softball) stood still and just threw it forward. I explained that with no forward momentum generated from the lower half of my body I can only throw the ball so far and so hard. Then I did a full pitching windup and threw the ball much harder.

I explained the basics of potential energy, mass shift and momentum that cause the velocity of pitch to be faster when thrown via the windup. I explained the windup for the pitcher acts like the top of the arc of a swing allowing him to build up speed as he propels his mass forward.

I tried to get into the conservation of angular momentum but I lost my student's interest at that point as she walked away to play with some dolls.

Either way good talk!

Sats for all, GR