Does Hitting the Ball on the Sweet Spot actually make the ball travel

Does Hitting the Ball on the Sweet Spot
actually make the ball travel farther ?
Samantha Harris
8th grade/Marshall Middle School/Mrs. Gillum
Introduction/Statement of the Problem/ Purpose
Every softball player wants to hit a home run. For most young players, it’s very difficult to hit one. Hitting a home
run requires the ball to be hit in the perfect spot on the bat. The perfect spot is commonly known as the sweet spot. But
what is the sweet spot exactly? The sweet spot is the area on the bat that has the highest hit-ball speed and the lowest
vibration.
Many players cannot find the sweet spot on their bat, or they do not know why the sweet spot is important. There
are lots of technical terms that try to explain it. Hitting the ball on the sweet spot, along with a few other key things,
makes a difference on how far the ball will go. It also leaves the least amount of sting in the batter’s hands. What does it
take to hit the ball on the sweet spot and really make the ball go over the fence? This problem is important because
players want to improve their batting percentage. Players need to know the mechanics of a hit and how to pick the right
spot on the bat to focus their batting practice.
Every softball player wants to hit a home run, but for many it is not the easiest thing to do. In order to hit a home
run some necessary things must happen such as hitting the ball in the sweet spot, at the right angle, and applying enough
force. This experiment hopes to discover a relationship between hitting the ball in the sweet spot, the angles of trajectory,
and how far the ball will go. There are many factors in hitting a home run, not just hitting the ball on the sweet spot.
Some of the factors are, the speed of the bat, the horizontal angle, vertical angle, and timing of when the bat and the ball
meet.
The purpose of this project is to determine the best place on the bat, to hit the ball, which makes it go the farthest.
Part of this experiment is to determine the different factors that contribute to hitting the farthest ball. The other part is to
determine if hitting the ball on the sweet spot is the key factor in hitting a home run. The sweet spot is the place on the bat
where there is the least vibration. It also has the maximum hit-ball speed. There have been two different places on the bat
that have been called the sweet spot, the center of percussion and the nodes of vibration. There has been no clear
explanation to hit a home run and this experiment will try to provide these answers.
Previous Experiments
Samuel In, a former student at Marshall Middle School conducted an experiment called The Sweetest Bat: What makes a bat
better than another? His experiment tested the correlation between sound amplitude, the sweet spot of the bat, and the hit-ball speed. His
hypothesis was that at least 80% of the bats with the lowest sound amplitude within both the sweet spot and the sweet area will have the
smallest range in ball exit speed. Samuel In built a bat-swinging machine to test his hypothesis. Each bat was measured for hit-ball speed and
sound amplitude at every two inches from the handle to the end of the bat. The results proved the hypothesis wrong; however, he did find
76.92% met his criteria. He also asserted that the swing is more important than the bat itself because many of the bats had similar hit-ball
speeds.
The report helped explain hit-ball speed and the sweet spot, as well as the different hit-ball speeds by the bat brand. However, it did not
explain why sound from the hit matters. Samuel did test all three different types of bats: aluminum, composite, and wood, which helped
explain how they are different. It did explain how measurements of hit-ball speed were made. Also, for each bat, it did identify the sweet spot
location on a graph.
The sweetspot of a hollow baseball or softball bat, an experiment conducted by Daniel A. Russell, Ph.D, was to discuss different
definitions of the sweet spot. He creates two groups of definitions: maximum ball speed and the minimum hand sting. The first one, the center
of percussion, is often thought to be the sweet spot, but the center of percussion is not specific spot on the bat. Russell also discusses the first
two bending modes as the definition of the sweet spot. He states most bats have different size sweet spots; the sweet spot is about 5-7 inches
from the end of the barrel. Another definition is minimum hand sensation, which is the area between the first bending node and the center of
percussion. The location of maximum performance has two definitions: collision efficiency also known as coefficient of restitution and batted
ball speed.
This project showed that there are many definitions of the sweet spot. It also showed that each bat may have to be measured to find
their specific sweet spot. The definitions of the sweet spot contradict each other making it vague. The article also showed that the sweet spot is
not a specific spot, but more of an area within the bat.
The RockBats Company located in Madison, Wisconsin conducted an experiment entitled Detection of the Baseball Bat Sweet Spot Through
Vibration Testing. They defined the sweet spot as the vibration pattern when a node of vibration coincides with the batters’ grip. The
experiment was to determine the vibration response of two wooden bats with the same length 33 inches and shape but with two different
densities. Sensors were attached to the handles of two bats, one 32.3 ounces and the other 29.5 ounces. Then, they collected data with the ball
contacting the bat in 1-inch increments from the handle to the tip. Detailed graphs showed the amplitude of vibration. After the primary
vibration spike, which makes the ‘crack’ sound of the hit, there is a secondary vibration the batter feels in their hands.
This project explained the relationship between density and vibration and how they are important to finding the sweet spot. The heavier
bat had a larger sweet spot than the lighter one, with less vibration response than the lighter bat. The project also revealed that lighter wooden
bats have a higher chance of breaking. In their project, they had a computer model to show where the stress occurred on the bat. The model
also showed how much the bat moves and the ball flattens on impact.
Core Science
In order to understand how to hit a home run, one must understand what actions lead to the right hit. Scientists believe that the
sweet spot is the place where the least vibration is felt in the batter’s hands and where the maximum hit-ball speed is. But one question still
remains, where is the sweet spot located on a bat? Both the center of percussion COP and the nodes of vibration have been called the sweet
spot. The center of percussion is the point opposite of the handle, somewhere near the end of the bat. A ball that strikes between the handle
and the center of percussion pushes the handle in the direction of the ball. A ball hit between the COP and the end of the bat pushes the
handle in the opposite direction of the ball. The center of percussion is like an off balance seesaw. The node of least vibration is the place
between the center of percussion and the end of the handle. The sweet spot is near the center of percussion and the node of least vibration.
In fact, a player doesn’t need to hold tightly onto the bat when the ball is hit in the sweet spot.
When the bat and the ball meet the energy from the bat is transferred to the ball sending the ball in the opposite direction. But the
farther the ball is hit away from the sweet spot, the more energy and speed is lost. The energy lost goes into the bat in the form of vibration.
The vibration is felt in the batter’s hands. Bat vibration hurts the batters hand closest to the impact. Most of the energy goes back to the
ball, and the ball compresses during impact. When the bat and ball meet the amount the ball can compress depends on different impact
velocities. The harder the impact velocity the more the ball compresses. After the ball compresses, it uses energy from the bat to go back to
its original shape. A bat ball collision is considered inelastic and described by a coefficient of restitution (COR). COR is the ratio of the ball
speed rebounding from the hard surface to its new speed. For example a ball traveling at 58 mph striking a surface and rebounding at 32
mph has a COR of 32/58 = 0.55. Based upon this, more than half of the energy is lost to friction.
Weather affects the flight of the ball. Wind is perhaps the biggest factor in hitting a fly ball. A tailwind can turn an ordinary pop fly
into a home run. A crosswind can push a fair ball foul. A headwind can turn a home run into an out. Hot weather causes air to expand,
creating less air pressure and less drag on the ball. Cold weather causes air to contract, creating more air pressure and more drag on the
ball. Elevation at a baseball stadium in Denver, Colorado is more than 5,000 feet above sea level. At this height the air is thinner which
causes less drag. San Diego stadium is at sea level where the air is thick, causing more drag. All aspects of weather affect how far the ball
can travel.
One way to test for the location of the sweet spot is fairly simple. This sweet spot test will locate the area of the least vibration.
While holding the butt end of the bat and letting it hang freely another person can hit the bat every inch upward. The person holding the bat
marks at the point where the vibrations stop. Continue striking the bat with the hammer until the vibration resumes. When the vibration
resumes, mark the end of the sweet spot.
Hypothesis & Materials
It is expected that that some balls hit in the sweet spot with extreme angles will not go as far as balls hit outside the sweet
spot, but with optimal angles of impact. Based on previous trajectory analysis, it was shown that changes in vertical angle affect
how far the ball will go. By examining the HitModeler, Dr. Nathan’s research showed that the ideal angle to hit the ball is between
35 and 45 degrees. Due to the variation of angles and location on the bat, the distance the ball travels will also vary. To account for
the variation a number less than 100% was chosen as a target value for the hypothesis which is when balls are hit in the sweet
spot zone, 90% of the balls will travel farther than the ones that are not hit in the sweet spot.
Materials
1. 10 different kinds of bats both aluminum and composite
2. One tee
3. One hammer
4. 50 little red flags
5. One tape measurer
6. Two different colors of tape
7. One batting machine
8. One bat vibration machine
9. One bucket of balls
Procedures
1. First the tee needs to be set up to a specific spot on home plate.
2. Using a tape measure, the distance of the hit ball will be recorded.
3. A seismograph will be attached to the bat, then the bat will be struck with
a hammer swung from a pendulum.
4. Each bat will be marked with tape to see the identified sweet spot.
5. Each bat will be tested separately to determine the different sweet spot zones
between each bat.
6. The ball will then be placed on the tee at home plate.
7. The bat attached to a swinging machine will then make contact with the ball.
8. While the bat and the ball meet, a person will be watching to see where the hit ball lands.
9. After the bat and the ball make contact, a person will mark where the ball has
landed using a little flag.
10. A tape measure will be used to find the distance and direction from home plate to
the little flag.
11. The distance between the two places will be written down for further analysis.
12. Each bat will hit 50 balls on varying places, and each hit will record the spot on
the bat and the distance and direction the ball travels.
13. Once all of data is collected, the data will be analyzed using analysis of variance
statistical method.
14. Then the distance will be compared to the other variables.
Observations & Results
The purpose of this experiment was to determine whether or not hitting the ball in the sweet spot of the bat makes
the ball travel farther. The data showed that the main “sweet spot zone” in both composite and aluminum bats was
between 3-7 inches from the barrel end of the bat. The main peak in distance of the batted ball traveled was 5 inches
away from the barrel end of the bat (mark 5.) The data in table 1 below are the average distance a batted ball traveled
after being hit. Each value is the average of 6 hits per mark.
Previous research showed another way to test where the sweet spot is on the bat. It is tests how much the bat
vibrates when it is struck with a hammer. When the bat was struck with a hammer it was proven that the area between
3-7 inches had the least vibration. These results corresponded to the results from hitting the ball with the bat machine.
When the bat made contact with the ball in the sweet spot (3-7 inches) the ball traveled farther. The range on the bat
where there is the longest hit distance and least vibration is the sweet spot of the bat, as defined as the area of least
vibration.
The aluminum bats tested had more consistent distances than the composite bats. Most of the aluminum bats were
lighter than the composite bats, which made it easier and faster to swing the bat. However, in the group of aluminum bats
there was an outlier. Bat 7 had longer hit ball distances than any other bat. In both the aluminum and composite bats the
mark where the balls had the farthest distance was 5 inches from the end of the barrel of the bat (mark 5.) According to
scientists, the place on the bat where the ball has the farthest distance and the least vibration is the “sweet spot.”
The composite bats tested showed that the distance the ball traveled was not as consistent as the distance the ball
traveled when using an aluminum bat. Bats 9 and 10 have a “flat line” in between marks 3 and 7, it shows that the
distance did not increase even though it was hit “within the sweet spot.” Many of the composite bats were heavier then
the aluminum bats. The heavier bats were not able to swing as fast as the lighter bats. The slower the bat swung could
cause the ball not to go as far as those that were lighter and could swing faster.
Another way to test the sweet spot is to see how much the bat vibrates when it is struck with a hammer. When the
bat was struck with a hammer it was proven that the area between 3-7 inches had the least vibration. These results
corresponded to the results from hitting the ball with the bat machine. When the bat made contact with the ball in the
sweet spot (3-7 inches) the ball traveled farther.
Data Tables/Graphs Summary
Softball Batted Ball Distance 85.0 80.0 Inches 75.0 70.0 65.0 60.0 55.0 50.0 45.0 1 3 5 7 9 11 1 67.7 62.4 64.2 64.9 57.3 51.7 2 59.8 68.7 71.4 68.3 63.3 51.8 3 68.0 73.3 76.7 75.3 66.8 66.3 4 63.4 70.1 72.6 68.7 60.3 56.0 5 64.1 70.4 71.3 65.0 60.5 57.3 6 57.8 61.7 64.6 63.5 55.3 46.7 7 67.9 73.1 80.8 75.8 71.4 60.5 8 61.3 66.4 67.3 66.4 61.3 51.2 9 67.2 76.8 76.8 69.2 60.3 50.8 10 57.3 61.8 61.6 61.1 54.5 47.3 The graph above shows the distance in inches the ball traveled after it was hit on a specific bat using both aluminum and
composite bats. The numbers 1, 3, 5, 7, 9, and 11 represent the marks (in inches) from the barrel end of the bat where the ball was hit.
The numbers 1, 3, 4, 5, 7, 9, 10, 11, 12, and 14 represent the number of the bat that was tested. Each color represents a different bat.
Data Tables/Graphs Summary Composite Bats Batted Ball Distance 85.0 80.0 Inches 75.0 70.0 65.0 60.0 55.0 50.0 45.0 1 3 5 7 9 11 1 67.7 62.4 64.2 64.9 57.3 51.7 2 59.8 68.7 71.4 68.3 63.3 51.8 6 57.8 61.7 64.6 63.5 55.3 46.7 7 67.9 73.1 80.8 75.8 71.4 60.5 9 67.2 76.8 76.8 69.2 60.3 50.8 This graph shows the distance the ball traveled using the composite bats. The numbers 1, 2, 6, 7, and 9 represent the
composite bats. The numbers under the numbers 1, 3, 5, 7, 9, and 11 are the average distances the ball traveled after being hit.
The numbers 1, 3, 5, 7, 9, and 11 represent the marks on the bat (in inches) where the ball was hit starting from the barrel end.
Data Tables/Graphs Summary 80.0 Aluminum Bats Batted Ball Distance 75.0 Inches 70.0 65.0 60.0 55.0 50.0 45.0 1 3 5 7 9 11 3 68.0 73.3 76.7 75.3 66.8 66.3 4 63.4 70.1 72.6 68.7 60.3 56.0 5 64.1 70.4 71.3 65.0 60.5 57.3 8 61.3 66.4 67.3 66.4 61.3 51.2 10 57.3 61.8 61.6 61.1 54.5 47.3 This graph shows the distance in inches the ball traveled after being hit using an aluminum bat. The numbers 3, 4, 5, 8, and
10 represent the aluminum bats tested in this experiment. The numbers 1, 3, 5, 7, 9, and 11 represent the mark where the bat met the
ball in inches from the barrel end of the bat. The numbers below 1, 3, 5, 7, 9, and 11 show the average distances of the balls hit on
that mark.
Conclusions/Recommendations
In this experiment, the results showed that 6 out of the 10 bats hit mark on mark 5 traveled the farthest distance. The bats
that had mark 5 as the peak in the distance were bats 3, 4, 5, 7, 9, 11, and 12. Out of those 6 bats, 3 of them were composite.
The other 2 of those bats were aluminum. Bat 4 was the only bat that was aluminum with a composite neck. It was proven in
this experiment that the sweet spot zone was between 3-7 inches from the end of the barrel of the bat.
After the distance test the bats were tested for the variation of vibration. The results of the vibration tests showed that 8
of the 10 bats “ideal” spot to hit the ball were at mark 5. The results of all the bats’ vibration also showed that the sweet spot
zone is the area on the bat with the longest hit ball distance and the least vibration in that area of the bat. When the bats were
tested for hit ball distance, it was not possible for the heavier bats (21oz+) to swing as fast as the lighter bats. This situation
would also apply to a real hitter’s performance.
Bat 7 had the longest hit ball distance on all areas of the bat. Bat 10 had the least hit ball distance along all of the marks
on the bat. Bat 7 was the Easton Z Core model ST7-ZB 32” 22oz and aluminum. Bat 10 was the Easton Synergy model SRV1B
33” 23oz and composite. When the bats were graphed, the composite bats did not have as much consistency in hit ball distance
as the aluminum bats had. Out of the composite bats bat 9 was the highest preforming in hit ball distance. Bat 10 was the lowest
preforming composite bat.
The experimenter’s results were accurate and a reliable. However some changes could be made to improve this project.
First, one main thing that could be improved on is that the vibration tester wasn't the most accurate sensor. This project would
have had more accurate results if the vibration tester was more high quality. Another thing that could be improved on in this
project is the force applied to the ball when it was hit with the batting machine. The bat hitting machine was not an accurate
representation of a real softball player. The hitting machine had too much force on the ball to accurately imitate the swing of a
softball player.
Furthermore, the batting machine’s stability could have been improved. Because of the added force to the ball once it
was hit, it caused the hitting machine to sway back and forth. The hitting machine was too light and the only way to hold it
down was with sandbags. Also, the ball was placed on the tee slightly different every time, this could have affected the
performance of a bat. In addition, during the vibration testing, the hammer was pulled back slightly different every time, thus
could have caused the bat to have a higher or lower performance. One of the most important improvements that could be made
is the way to more accurately measure the hit ball distance. In the experiment, using flags to mark where the ball landed could
be off when the flag was placed into the ground.
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