# Swing That Bowling Ball

September 7, 2019

Wait — why are those bowling balls swinging? They’re showing what happens when YOU ride a swing. No matter how far you push back or how much you weigh, it always takes the same amount of time to swing from back to front. The only thing that changes the timing is the length of the chains. Longer swings take longer. In this amazing video, all those colorful bowling balls hang at slightly different heights. They start swinging together, but soon separate in a ripple, clinking xylophone bars to prove it. Watch the video to see — and hear it!

Wee ones: What shape is a bowling ball? Can you find that shape in your room?

Little kids: If 1 bowling ball swings 3 feet above the ground and another swings 4 feet above ground, which one is higher?  Bonus: If there are 14 balls between the first and last, how many are swinging in total?

Big kids: After every one of the 16 balls has made 4 full round trips (right to left and right again), how many notes have you heard them clink in total? (They clink at both the front and back.)  Bonus: If the balls play the musical notes C, D, E, F, G, A, B, then C to start the pattern again over, what note does the 16th ball play?

The sky’s the limit: If the slowest-period ball takes 5 seconds to swing from front to back, the one in the middle takes 4 seconds, and the fastest-period ball takes just 3 ½ seconds, how many seconds will it be before they all line up again on the right?