Air is all around us, but because we can’t “see” it we often don’t realize it’s power. Because of this, experiments dealing with air pressure are fascinating and often leave us scratching our heads wondering how they work.
This experiment definitely falls into that category, because the results are likely different than one would initially guess. Because of this, make sure to ask your kids to hypothesize what will happen to the ping pong balls before you conduct the experiment.
Air Pressure Impact on Ping Pong Balls Video
- 2 Ping Pong Balls
- String (2 piece of string each 2+ feet long)
- Drinking Straw
- Stationary Object to hand strings from (i.e. Door Frame, Shower Curtain, Clothes Drying Rack)
Step 1 – Gather two ping pong balls, and cut two pieces of string that is 2 feet in length or longer (length will depend on where you are hanging the string from)
Step 2 – Tape one end of one piece of string to the first ping pong ball. Tape one end of the other piece of string to the second ping pong ball.
Step 3 – Hang the other end of the string to a stationary object. The objective is for the ping pong balls to hang freely in the air at the same level and about 4 inches apart.
Helpful Tip: We used a clothes drying rack. You could also tape them to a door frame or hand them to a shower curtain rod.
Step 4 – Make sure the ping pong balls hang in mid air at the same height about 4 inches apart.
Step 5 – Use a drinking straw to blow air directly in between the ping pong balls. Position yourself so the straw is level with the ping pong balls and about 4 to 5 inches behind them. What happens to the ping pong balls when you do this?
How Does the Experiment Work?
Air pressure is the secret to this experiment.
The faster air is moving the lower it’s pressure is. Therefore, the air that you blow in between the ping pong balls has a lower pressure than the air on the outside of the ping pong balls.
Said another way, the air on the outside of the ping pong balls has a higher pressure than the air in between the ping pong balls. This high pressure air moves toward the lower pressure air and it pushes the ping pong balls together in the process.
More Science Fun
If you are looking for more experiments dealing with Air Pressure then you’re in luck. Check out these other fun and simple experiments we’ve done that show the power of air.
- How to crush a plastic bottle
- Use a simple science “trick” to easily stab a regular drinking straw through a raw potato
- Or turn a Water Glass upside down without spilling the water!
- And you can even make a balloon fly across the room like a rocket
I hope you enjoyed the experiment. Here’s some printable instructions