Celebrate Chemistry...Finding Baseballs Sweet Spot

The Science Mommy has been invited by Dow Chemical to Celebrate Chemistry this summer!

Here's what's happening...The Science Mommy hosted a Chemistry Party and will post the investigations over the next two weeks.  Each week you'll have a chance to win!

Ages: This investigation is best for the Big Kid Scientists

Materials:Bat, 2 meter sticks, baseball, golf ball, tape

There is a bit of prep for this investigation.  Depending on the age of your Kid Scientists, you could have the prep work done ahead, or the Kids could do it themselves.

Procedure:

• Mark off 4 cm sections of the bat as shown in the photo.  The Science Mommy only had a kids bat available at home and the investigation worked well.  We tried it later at a friends baseball practice, with a full sized bat and it worked even better.

• Kid Scientists should hold the bat, straight down, in one hand.  Hold the bat's handle loosely between the thumb and the first finger.
• With the golf ball, tap the bat in each marked off section.  Ask Kid Scientists what they felt when you tapped the bat.  Was there a section in which the vibrations felt stronger, or a section in which they weren't as strong.
• Ask other Kid Scientists in the group what they heard when the bat was tapped.  Was there a section that was louder, or where they could hear more vibrations?  Give each Kid Scientist a chance to hold the bat and feel the vibrations.  This is a great opportunity to talk about how we make observations through feeling and hearing.

•  This step requires a little balance and practice.  Tape the two meter sticks together in an "L" shape to form a ramp.  Place the bat on a box or a stack of books and ask one Kid Scientist to hold it firmly.  Lean the meter stick ramp against the bat and ask another Kid Scientist to hold the ramp.  
• Roll the golf ball down the ramp to the bat so that it bounces off the bat in Section A. Measure the height of the bounce based on the meter stick. Once the kids know what the procedure looks like and feels like, you can talk about conducting a controlled investigation.  The Kid rolling the ball should start the ball in the same position each time.  The ramp should stay at about the same angle to the bat.  Kids could roll the ball three or four times in each section and average the data collected.

• Connar collected the data while Emma rolled the ball down the ramp.  Continue this process for each section of the bat.  Where does the ball bounce the highest?  The spot on the bat where the ball bounces the highest is the Sweet Spot!

What's Happening? The sweet spot we found is called "the node", where vibration waves from the impact of the bat and ball cancel each other out.  At the node, more of the bat's energy goes to the ball because it's not used up in vibrations.  When you hit a ball with the node of a bat, you don't feel any vibration in your hand and the ball goes further because it has more energy behind it.

Watch this video to learn more about: Finding the Sweet Spot

To Enter the Give-A-Way: You must be a follower of The Science Mommy and enter a comment on a Celebrate Chemistry post.  There will be three posts, and you can enter with each post.

Additional entries:  Send the Science Mommy a picture or link to your Science Mommy project and you will receive an additional entry.