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Do your grandkids watch Cocomelon? Recently, I was watching with my grandson and saw them racing cars via a deflating balloon. (If I recall correctly, the lyrics said something along the lines of “blow your balloon up, blow blow blow, it’s time for the race.”) This got me thinking: Does this actually work?
Spoiler alert: It does, and it is a very fun activity that both you and your grandkids will enjoy! Before you get started, however, you will want to collect the following items:
- A small, lightweight rectangular piece of cardboard (this will be the base of the car)
- 4 plastic bottle caps (for wheels)
- 2 straws (for axles)
- A balloon
- A plastic or paper cup
- A rubber band or two (optional, for added thrust)
1. Prepare the wheels and axles
To begin, cut the straws into two pieces, each long enough to fit the width of the cardboard. Using the scissors, make a small hole in the center of each bottle cap and slide each straw piece through two bottle caps, ensuring the caps can rotate freely.
2. Attach Wheels to the Base
Tape the straw axles to the underside of the cardboard base, making sure the bottle cap wheels touch the ground and can spin freely.
3. Set up the balloon propulsion
Inflate the balloon slightly (do not tie it off) and let the air out to stretch it a bit. Attach the balloon to the short end of a straw using a rubber band or tape. Ensure the opening of the balloon is secured and that air can pass through the straw when the balloon is inflated. Tape the straw (with the attached balloon) to the cardboard base, ensuring the straw points towards the back of the car.
4. Race your balloon cars
Inflate the balloon through the straw, pinching the end of the straw when it’s fully inflated to trap the air. Place your car on a flat surface, let go of the straw, and watch it zoom away!
- When the balloon deflates, it pushes the air out through the straw. According to Newton’s third law, the force of the air exiting the balloon (action) propels the car forward (reaction).
- Experiment with different sizes and shapes of balloons, or the angle of the straw, to see how these changes affect the car’s speed and distance.
- Discuss friction and how smoother surfaces might make the car go faster while rougher surfaces might slow it down.
This activity is sure to provide loads of entertainment, and it’s a fantastic way for grandmas and grandkids to bond while learning together! Have fun and good luck! 😉