Science Smarts: Screaming balloons
By PATTY ROOKS on July 29, 2023.
What a wonderful (yet busy) week it has been. I have enjoyed seeing all of the stores decorated for Stampede, the pancake breakfasts, the amazing parade and being part of the Methanex Kiddies Days in Pioneer Village once again really topped off the week for me. In case you were not able to make it to the Stampede to do some exciting hands on science activities, I will share one of my favourite with you. Let’s get started! *Remember to ask an adult before doing this experiment. Materials • Balloon • Quarter-inch hex nut Procedure • Squeeze the hex nut through the mouth of the balloon. Make sure that the hex nut goes all the way into the balloon so that there is no danger of being sucked out while blowing up the balloon. • Blow up the balloon, but be careful not to over inflate it, as it will burst very easily. • Tie off the balloon and you’re ready to go. • Grip the balloon at the stem end as you would a bowling ball. The neck of the balloon will be in the palm of your hand. • While holding the balloon palm-down, swirl it in a circular motion. The nut may bounce at first, but eventually it will begin to roll around the sides of the balloon. • Hear that sound? • Once the nut begins to spin, use your other hand to stabilize the balloon. The sounds should continue for almost 10 seconds after the balloon has stopped moving. What is Going On? Today we’ve learned about two things: centripetal force and producing sounds. Centripetal force is the inward force that acts on an object moving in a circular path. So as the balloon spins and the hex nut travels in a circle around the balloon, there is a ‘centre-seeking’ force acting on the nut. In this experiment the nut vibrates the balloon and produces sound. A hex nut has flat sides. These flat sides slide, bounce and vibrate along the inside of the balloon. These movements cause the balloon to vibrate and produce sound. If you were to complete the activity and put a dime in the balloon instead of the hex nut, the dime would demonstrate centripetal force, but would not produce sound because a dime is round. The round dime would glide much easier over the balloon surface and not produce any sounds. Patty Rooks, Senior Scientific Consultant PRAXIS, “Connecting Science To The Community”. Contact Praxis at praxis@praxismh.ca, http://www.praxismh.ca, Tweet or follow us @PraxisMedHat, or friend us on Facebook. Address: #12 826 11 Street S. E., Medicine Hat, Alberta, T1A 1T7 Phone: 403-527-5365, email: praxis@praxismh.ca. 20-19
