Science Buddies: "Ask an Expert"

I need to know how best to construct something that will suspend a soccer shoe, weighted to simulate a real foot/leg, allowing it to swing down and kick a soccer ball. I am trying to see if there is any difference in the distance in a ball that is kicked while cold vs a ball kicked while hot.

Another spin on this experiment would be to inflate the ball to different pressures.

The air pressure in the ball will be different when the ball is hot or cold, if the temperature difference is great enough that is what you will be measuring anyway. Though the ball material will have temperature related issues too, the air pressure could be the best data.

You could get more reliable data by inflating to different pressures.

As far as giving it a kick, how about a pendulum that will strike the ball with whatever, it doesn't have to be a shoe. Pulling back the pendulum to the same point will give it the same "kick" everytime.

Jim

For simplicity and consistency I suggest you go with the pendulum from Jim’s post. If you really want to use a real shoe, I recommend you ask a local shoe store for one of the shoe inserts that they use to displaying the shoes. Sometimes these are made of metal and wood or plastic (or try a thrift store). This would allow you to put a shoe on it relatively easily hang it from a rod so it could swing and you could also add weight to it.

This looks like a very interesting project. I would go for the gold. See if you can find a store that will let you BORROW a leg from a manequin. You could not damage it and you would need a shoe for it, but think of the visual impact of the demonstration.

Second possibility: Look in the yellow pages under orthopaedist, call one on the phone and ask for a referral to the local craftsman who makes artifical limbs. They may have one on the shelf that someone no longer needs. I peeked in the back door of one of these guys who has an office next to my dentist. His back room had arms and legs scattered all over the place, as if he could not part with his prior work.

Post a followup and let us know what you did.

Robert Reavis

I play soccer so when I saw this experiment it really interested me. My dad is a physical therapist who works with elderly patients so I have seen a prosthetic leg before. I just wanted to let you know that I think that your project is an awesome idea, and you should definitely go for the gold, like Robert Reavis said, but I think that you should use a prosthetic leg. It would really spice up the appearance. Also with a prosthetic leg, you could put a cleat, and even a shin guard and soccer sock on the leg! Hope this helps!