# Let’s Bounce

May 11, 2020

When you drop a ball, it bounces back up, but not to the same full height. What happens if you drop a ball on top of a ball on top of a ball? Physics Girl stacked up a golf ball on top of a bouncy ball on top of a basketball. When she dropped the stack, the basketball and bouncy ball rocketed the golf ball way up into the sky – 28 feet! That’s more than 8 times the height the golf ball started from – or a tower of 35 basketballs, or 200 golf balls.

Wee ones: Find a ball of any size. Drop it without throwing it down, and see how high it bounces. Does it bounce as high as your hand?

Little kids: If 3 friends each drop a stack of 3 balls, how many bouncing balls is that? Bonus: If each story of a building is 10 feet tall and you stand on the roof of a 2-story house, does that golf ball bouncing to 28 feet stop above or below you?

Big kids: If this stack made the golf ball fly 8 times its starting height, how high would the golf ball fly if a stack was dropped from a 20-foot-tall diving board? (Onto the pavement, not into the pool!) Bonus: What if you could bounce 8 times your height? How high would that be in feet and inches?