Science Buddies: "Ask an Expert"

I was given an inquiry question that involves me making a machine to swing a baseball bat. I have absolutely no idea how to create this device. I have to use 3 identical bats filled with different masses, but the velocity of the swing and the angle on where the bat hits the ball must stay consistent. Anyone have any ideas on how to create this???

Hello youto888,

I'm sure there are very many ways to build a machine that could swing a bat. I'll guess that you want a simple, easy-to-build version.
How about building a frame of wooden 2x4 boards. Use a door hinge to attach the bat to a side of the frame. Get a spring to pull the bat through its swing. Install a post just below the swing of the bat to support the ball. Pull the bat back to a fixed location and let it go.
Of course, even within the description I give, I'm sure you can think of many variations.
Remember that the effect of hitting a stationary ball will be quite different from hitting a fast ball, but the result should be consistent from trial to trial.

Also, Please note that when the bat swings, it could be deadly if someone were in the way. Use a small spring to limit the danger. There's no reason that you have to hit the ball a long distance to test your question. Operate it manually and take great care.

Good luck.

I did a quick internet search and cape up with the description of how some students built a bat swinging device:

http://tuhsphysics.ttsd.k12.or.us/Resea ... htm#making

It looks pretty simple and similar to the ideas that Wendell passed on to you.

Have fun with your project!