| Effect of Arrow Tip Mass on Penetration into a Cardboard Target | |
Researched by Kevin B.
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The purpose of this experiment was to determine which weight of arrow tip would penetrate deepest into a target material.
I became interested in this idea when I found out that if a bow hunter hits a game animal, it doesn’t always die instantly, so I wanted to do a test to see which weight of arrow would penetrate best to help prevent needless suffering.
The information gained from this experiment will help archers and bow hunters so they can use arrow tips that penetrate better. It will also benefit the animals so they die instantly and don’t have to suffer if they get hit with an arrow.
My first hypothesis was that the 125-gram tip would penetrate the deepest. My second hypothesis was that the 65-gram tip would have the least amount of penetration.
I based my hypothesis on what Eric Van Epps, the manager of an archery shop told me. “Kinetic energy is a formula used to measure the force of an arrow at impact. The greater the arrow weight, the more kinetic energy causing deeper penetration. ”
The constants in this study were:
- Type of bow
- Width of target
- Material of target
- Area of target
- Force of drawback
- Temperature of testing environment
- Arrow brand
- Arrow tip design
- Length of arrow shaft
- Fletching of arrow
- Type of arrow
- Distance from target to bow
- Number of tests per arrow tip weight
- Testing procedure
The manipulated variable was the mass of the arrow tips.
The responding variable was penetration into the target.
To measure the responding variable I made a mark on the arrow at the surface of the target. Then I measured the distance from the tip of the arrow to the mark in millimeters.
| QUANTITY | ITEM DESCRIPTION |
| 1 | Bow (42lb draw) |
| 4 | Arrows |
| 5 | 65-gram arrow tips |
| 5 | 85-gram arrow tips |
| 5 | 100-gram arrow tips |
| 5 | 125-gram arrow tips |
| 1 | 20-centimeter thick cardboard target |
| 1 | Black marker |
| 1 | Journal |
| 1 | Archery stand |
| 1 | Supporter for target |
| 9 | Boards of 120 cm x90 cm cardboard |
| 1 | Cardboard cutter |
| 1 | Bottle of wood glue |
SAFETY PRECAUTIONS
1. Never point drawn bow at any object or animal you don’t intend to
hit.
2. Never shoot an arrow unless the area is free of people or animals.
3. Never shoot an arrow straight up.
4. Keep equipment in good condition.
5. Always have an adult supervise you during the experiment.
Making the Target:
1. Have an adult use the cardboard cutter to cut all of the corrugated
boards into 40 cm x40 cm squares.
2. Keep gluing the squares together until they make a rectangle with
a thickness of 20 cm. Make sure to glue along the outside part of
the square’s face and not in the middle.
3. Mount the target on the archery stand.
The Experiment:
1. Preferably use a field at least 100 yards away from houses to conduct
the experiment.
2. Set up target of 20-centimeter thick high quality cardboard.
3. Measure 30 feet from the target and place a marker at that spot.
4. Take the arrow with the 65-gram tip and draw the bowstring back
with 42 pounds of draw weight.
A. Look through the sight and release the arrow string.
5. Lay the bow down and grab your marker and ruler.
6. Walk over to the target.
A. Mark the part of the arrow along the target with a marker.
B. Remove arrow.
C. Measure with the ruler from the tip of the arrow to the mark.
7. Record the distance in your data table.
8. Repeat steps 4-7 two more times with a 65-gram arrow tip.
9. Repeat steps 4-7 with 85, 100, and 125-gram arrow tips.
The original purpose of this experiment was to determine which weight of arrow tip would penetrate deepest into the target material.
The results of the experiment were that the 65-gram tip penetrated the deepest with 92. 7 millimeters on average. The results of this experiment also indicate that the 85-gram tip had the least amount of penetration with 81. 3 millimeters on average.
My first hypothesis was that the 125-gram tips would penetrate the deepest. The results indicate that this hypothesis should be rejected because of the fact that the 65-gram tips penetrated deepest.
My second hypothesis was that the 65-gram tips would have the least amount of penetration. The results indicate that this hypothesis should be rejected as well because of the fact that the 85-gram tips had the least amount of penetration.
After looking at my data and reexamining the arrow tips, I noticed something new. Even though I bought the same kind of arrow tips, they weren’t exactly the same shape. The 65-gram tip didn’t have as much of a collar as the other weight classes, therefore producing a smaller amount of friction as the 85, 100, and 125-gram tips. The size of the collars on the tips increased as the weight did, possibly creating more friction.
Because of the results of this experiment, I wonder if the weight of an arrow would affect the maximum distance the arrow would travel or if the weight of the tip affects the accuracy of the arrow. I also wonder if the results would change if the arrow tips were exactly the same size collar, but had different weights.
My findings might be useful to bow hunters because the results were all within 10 millimeters of each other.
If I were to conduct this project again I would use arrow tips with greater weight differences. I would also conduct more trials and use a bigger target. I would have also used different types of bows. I would also use a more powerful bow. I could have shot the arrows from different distances away.
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Introduction The bow and arrow is a tool that has been used for thousands of
years for many purposes that range from hunting to competition. Many
various energies occur when using the bow and arrow.
Archery is the art or skill of using a bow and arrow. One type of archery is target archery, where people compete in hitting a color-coded target. Another type of archery is flight archery, where people compete for distance. Field archery is a type of archery where people hit a target, but usually just for practice or fun. History of Archery Around 25,000 B. C. , the first stone arrowheads were made in Africa. This indicates that the bow and arrow were invented there. At 5,000 B. C. the Egyptians needed bows and arrows for hunting and warfare. Crossbows, a type of bow, were first mentioned in China around 1,250 B. C. In 552 A. D. the Battle of Taginae took place. The Byzantine emperor, Justinian I sent his commander, Narses, with an army of 20,000 archers into Italy where at the Apennine village of Taginae he defeated the Goths. People today still use the bow and arrow for needs of their own. Bows A bow is a long stave of strong, flexible material, which is bent and held under tension by the bowstring. The main types of bows are the recurve bow, the compound bow, and the longbow. The compound bow has a series of cables and pulleys, which reduces the amount of force needed to pull the bowstring back. The core of a bow has several layers of wood that have been glued together. The bowstrings are usually made of plastics or polyethylene cord. The bowstring has a nocking point where the notch of the arrow fits. The bow’s body is usually made out of wood, carbon, or fiberglass. A self-bow is made of one material, built bows are joined pieces of the same material, and composite bows are made of different materials. Arrows An arrow is a projectile shot from a bow. The shaft is the body of the arrow. Aluminum shafted arrows are fast and accurate. The shaft can also be made of carbon composite. The fletching of the arrow is usually made out of plastic or three to four feathers. The fletching helps the arrow stay accurate in flight. There are different tips on arrows for different purposes. The tips are usually made out of metal. Bow hunters use tips with two or more cutting edges. Target and field archers use a conical, bullet shaped point. Momentum Momentum is the quality of motion of a moving body. Momentum is a conserved quantity, which means within a closed system of interacting objects, the total momentum of the system doesn’t change value. The formula for momentum is mass x velocity. When an object is moving, it has a non-zero momentum. If the object is still, then the momentum is zero. Momentum is a vector, which means it has a magnitude and a direction. Kinetic Energy Kinetic energy of an object is the energy it has because of its motion. Kinetic energy is an expression of the fact that a moving object can do work on whatever it hits. It quantifies the amount of work the object could do as a result of its motion. Some types of kinetic energy are vibrational, which is energy due to vibrating motion. Rotational, which is energy due to rotating motion and translational, which is energy due to motion from one place to another. Kinetic energy depends on two variables: mass and velocity of the object. The formula for kinetic energy is 1/2 x mass x velocity squared or 1/2 MV2. Summary The bow and arrow uses translational kinetic energy, or energy due to motion from one location to another. As arrow mass increases, so does its kinetic energy. Bow hunters have to decide which tip to use, depending on whether they are hunting turkey or deer. Archery is still practiced today with many variations of bows and arrows and will likely be used for future generations. |
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Brissee, Tom. “History of Archery. ” Strictly Bow Hunting. December 10, 2003 <http://www. strictlybowhunting. com/Anov01issue/history_of_archery.htm > “Definition of Momentum. ” Momentum. January 4, 2004 <http://id. mind. net/~zona/mstm/physics/mechanics/momentum/momentum.html> Graeme, Jeffery. “A Shot in Time. ” Centenary Archers. October 29, 2003 <http://centenaryarchers. gil. com. au/history.htm> Henderson, Tom. “Energy. ” Kinetic Energy. November 16, 2003 “Kinetic Energy. ” Energy. January 4, 2004 <http://hyperphysics. phy-astr. gsu. edu/hbase/ke.html> “Martin Archery,” Martin Archery. November 5, 2003 <http://www. martinarchery. com/> Murray, Andrew. “Archery,” British Library. October 29, 2003 <http://pages. britishlibrary. net/thirskbowmen/index.htm> National Archery Association of the United States. “Archery,” ENCARTA Encyclopedia Deluxe, 2001. National Archery Association of the United States. "Archery," World Book Encyclopedia, 2002. Volume 1, pages 601-604 Stover, Ed. “Aiming Higher,” Yakima Herald Republic Newspaper. October 12, 2003. <http://www. yakima-herald. com/> Stuke, John. “His Life’s Now on Target,” ProQuest Online Articles. September 26, 2003 <http://proquest. umi. com/pqdweb> Van Epps, Eric. Personal interview. November 16, 2003 |
I would like to thank the following people for helping make my project possible:
- My parents for driving me to the after school classes and helping me conduct my experiment.
- Mr. Newkirk for correcting my report, holding after school classes, and giving me this opportunity to do this science project.
- Mrs. Helms for supporting me throughout my experiment.
- Kris Hudson for lending me her bow for the experiment.
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