Science Buddies: "Ask an Expert"

Dear ask an expert,
please help me answer these questioms
How much will the temperature affect psi level change on a ball?
In my experiment , I measure the distance on the first bounce. Is that the most accurate?
I did 3 trials of each psi level for a average. Should I gave done something different?
What is the most accurate tool used to measure psi?
In my experiment I used a size 4 soccer ball. What size soccer ball should I have to use?
In my experiment I am going to use my brother to kick the ball. should I use something else to be more accurate?
Is it better to measure with the ball on the ground or the air?
Does the footwear you wear affect the distance on the ball?
Does different psi pumps change the psi? Or is it the same?
Should you do the experiment with wind or no wind?

Thanks, sorry for a lot of questions!

Hi there,

Just to clarify--You will be answering the question how psi affects how far a ball can be kicked? Let me know if I've misunderstood your question!

Temperature will affect the observed psi in a ball, though I'm not sure how much. What I would suggest is to establish temperature as a control. If possible, have a thermometer to measure the temperature while you are recording your distances, and make sure it stays fairly steady. If you take all of the measurements within a relatively short amount of time you aren't likely to see a huge temperature change.

Since humans are very error prone, I'd suggest avoiding having someone kick the ball. This seems like a big source of error since it's very hard to kick with the same force every time! You are right that footwear would affect this as well. What you might do is drop the ball from a pre-decided height, and see how high it bounces next to a meter stick, etc.

https://www.sciencebuddies.org/science- ... cs#summary

Here is a project that sounds similar to yours. This outline should help answer a lot of your questions!

The soccer ball size is up to you. I would just make sure you are using the same ball as one of your controls.

Let me know if this helps, or if you have more questions!