This poster doesn't do it for me.
1. It looks like the dude is gonna miss the dunk.
2. I can't at all tell how much effort is being exerted.
3. The basketball is tiny and photoshopped.
4. It's not true.
That's the problem with all the posters you see at school. They're corny and they really don't mean anything. Mostly, they're just statements that do little to inspire kids. Still, I want my classroom to fit in... so made one of my own:
I think this will almost definitely make a difference in a child's life.