Field Trips
- Grade Level:
- Upper Elementary: Third Grade through Fifth Grade
- Subject:
- Science
- State Standards:
- Strand 3.3: Force Affects Motion
Standard 3.3.1 Plan and carry out investigations
Standard 3.3.2 Analyze and interpret data
Standard 3.3.3 Construct an explanation
Students will understand cultural factors that shape a community.
Students use digging sticks, throw atlatls, make fire with bow drills, and use rock wedges to explore the affects of friction and gravity on objects.
Essential Question: How did the inhabitants of the Four Corners area use tools to help them make everyday tasks easier 1000 years ago?
Utah State Science Core Curriculum Topic: Strand 3.3: FORCE AFFECTS MOTION. Forces act on objects and have both a strength and a direction. The patterns of an object’s motion in various situations can be observed, measured, and used to predict future motion. Forces are exerted when objects come in contact with each other, however some forces can act on objects that are not in contact. The gravitational force of Earth, acting on an object near Earth’s surface pulls that object toward the planet’s center.
Standard 3.3.1 Plan and carry out investigations that provide evidence of the effects of balanced and unbalanced forces on the motion of an object. Emphasize investigations where only one variable is tested at a time.
Standard 3.3.2 Analyze and interpret data from observations and measurements of an object’s motion to identify patterns in its motion that can be used to predict future motion.
Standard 3.3.3 Construct an explanation that the gravitational force exerted by Earth causes objects to be directed downward, toward the center of the spherical Earth.
Utah State Social Studies Core Curriculum Standard: Students will understand cultural factors that shape a community. Objective 1 Evaluate key factors that determine how a community develops. f. Explain changes within communities caused by human inventions (e.g. steel plow, internal combustion engine, television, computer).
Background:
Forces are pushes and pulls that can cause an object to change position, motion, or direction. The size and weight of an object can have a direct effect on the amount and type of force needed to cause these changes. Some forces are natural (i.e. gravity and wind). Other forces are manipulated by man (i.e. throwing an object towards another object or kicking a ball). Friction is a force that slows things. It acts in the direction opposite the applied force. Often, friction results in heat.
Humans always had to work for a living. During prehistoric times, people used natural materials to create tools to help them do their work. Wood, stone, bone, plants, shells, and animals provided the raw materials from which they made everything they needed. A considerable portion of modern technology builds on inventions made hundreds of years ago. Tools decrease the amount of human effort needed to create an intended motion. The atlatl is a long stick you hold in your hand, that acts as an extension of the arm to help propel darts.
The atlatl is one of humankind's first mechanical inventions. There is record of atlatl use in every continent except Africa, though perhaps evidence has yet to be discovered there. Though the bow and arrow mostly replaced the atlatl in 1000 B.C., atlatls have continued to be used into modern times in some parts of the world. Dart is the accepted term for an airborne weapon projected either by an atlatl or an arm. They are shorter and more flexible than a javelin, which is a is a heavier, longer pole without fletching and used without mechanical aid. In contrast, spears are shorter poles with a sharp end, not intended to be thrown. Darts are larger than arrows, with a weighted sharp point at one end, fletching and a nock at the other end.
At one end, the atlatl has a beak to hold the nock of a dart. To use the atlatl, you throw with a casting motion (as if you are fishing). A dart thrown with an atlatl has more impact force than a simple bow and arrow and has been known to penetrate car doors and armor. The darts travel at a much higher velocity than if thrown by hand. Atlatls were used for hunting in this area between 200 and 800 C.E.
Fire is a priority for survival. Humans use fire for warmth, to cook food, to make tools, and much more. There are many methods to start fires by friction. One method involves rubbing two sticks together to create charred powder. When enough powder piles up and gets hot enough, it will ignite. The small pile of dust or coal can be put into tinder and blown into flame.
One of the primary tools of the hunters and gatherers was the digging stick. It was also an important tool for the agricultural tribes. Archaic people began using the digging stick to dig edible tubers out of the ground and to dig for fresh water. Later, digging sticks were used to plant seeds. The wedge-shaped bottom can be fire hardened to add strength to the stick, making it easier to separate the soil. Once the digging stick is in the ground, it acts as a lever to lift the load it needs to get out of the ground.
Digging sticks were used to dig up potatoes and other tubers. Archeologists have found potato flour (from the Four Corners Potato, native to Utah) on grinding stones, or metates in a cliffside shelter in south central Utah dating to 10,000 years ago. Other foods gathered with digging sticks include wild onion and the Sego Lily.
Stone tools were also important to people 1000 years ago. When slicing and cutting, stone tools are used as a wedge. Stone knives and scrapers can be used in preparing leather, skinning animals, and processing meat. Materials like flint, chert, and obsidian were traded all over North America for making stone tools. Flintknappers strike the stones in a controlled manner to create sharp edges. The edges are so durable they don’t need to be sharpened like metal knives. Greg Nunn, a local flintknapper, made our replica scrapers sized specially for 3rd graders.
How far can I throw it?
Essential Question: How do forces cause motion?
Materials: An atlatl and dart: fire bow: stone tools: ¼ sheets of paper (1 per student); Force and Motion poster: atlatl youtube video link Atlatl Demonstration - YouTube
Procedure:
1) Introduce students to the phenomenon: An atlatl can hit a target fifty feet away. Show the actual atlatl and dart, and describe its advantages compared to hunting with a spear. Show a video of an atlatl being used. Have students brainstorm what variables affect the distance the spear is thrown.
2) Ask students to think about how throwing a ball of paper is like throwing the dart with the atlatl. Tell students they will get to see how arm length changes how far the paper is thrown. Hand each student a ¼ sheet of paper. Spread students out in a line across the classroom (make two groups if needed). Students should throw the piece of paper with only their wrist using a gentle toss. Observe how far the paper traveled and allow students to collect their paper. Then invite students to predict what will happen if they change how they throw the paper ball. Have them throw the piece of paper with their forearm and observe how far the paper balls traveled. Last, encourage students to throw as hard as they can with their full arm and compare the results. Instruct students to recycle their paper before returning to their seat.
3) Discuss their results and explain forces. If needed, review that a force is a push or a pull on an object. Ask students to consider in which test their balls traveled furthest. Explain (using the poster) this force is called their human “effort.” Ask students how they think forces affect the speed of the paper ball and the distance it travels. Use the poster to discuss forces acting on the paper ball that work against it going faster and farther such as friction in the air and gravity. Ask students to predict what happens to the direction or speed of motion if various forces are changed. Draw a model on the board, and add arrows as you discuss the following questions: Why does the speed your arm moves affect the way the paper ball moves? How does changing the angle you throw the paper ball affect the motion? How does gravity affect the system?
4) Show other inventions we will use on the field trip (fire bow and stone tools). Tell students that long before the pioneers came to this area, people called the Ancestral Puebloans lived here. The Ancestral Puebloans built the towers and stone structures we sometimes find in southeastern Utah. Explain they had the same basic needs as you and me. For example, they found and ate food, built houses, farmed or gardened, played, and had families. Discuss how the Ancestral Puebloans invented tools to help them.
5) Preview the upcoming field trip and emphasize the importance of safety (as some tools we are working with can be dangerous). Review the items students need to bring to school on the day of their field trip. (5 min)
Atlatls
*Safety is very important at this station*
Essential Questions: What forces act on a dart to affect its motion?
Materials: atlatls; darts; cardboard targets; atlatl poster; rope; target holders
Procedure:
1) Discuss with students what the people who lived here a thousand years ago ate. Although people gathered or farmed a lot of their food, they also hunted. Ask students about difficulties involved in hunting (i.e. some animals can be dangerous, it’s difficult to get close before the animal runs away). Show them the atlatl and demonstrate how it works. Tell students atlatls were used all over the world. Refer to the pre-trip and ask which toss made their paper fly further, using their entire arm or only using their wrist? The atlatl works to extend the arm, making it longer. Demonstrate how the atlatl helps a dart fly further. (3-5 min)
2). Show students the designated cold zone, warm zone, and hot zone and describe how to behave in each. The cold zone is the “safe zone” for students. In the warm zone, students need to be extra careful since this is where people may be standing and holding dangerous objects. Darts are thrown from the edge of the warm zone. The hot zone, beyond the rope, is the “danger zone” where darts will be flying. Inform students they will never cross the rope into the hot zone unless told to retrieve darts by an instructor. To keep everyone safe, anyone breaking this rule will be removed from the activity. (2-3 min)
3) Ask students if they have ever played a game or learned to do something new, like riding a bike or playing a sport, where they level up to do more advanced things. Tell them at this station there will be four levels to reach as a group.
Level 1: Dart safety (cold zone). Show students a dart. Ask students if they think it would be a good idea to stand in front of a classmate throwing a dart. Explain that to use this tool, they must be very safe. Tell students when they are holding a dart they must be in “safety stance”. Safety stance involves holding the dart with the tip on the ground. Hand each student an imaginary dart and practice safety stance. (2-3 min)
Level 2: Real Atlatl (warm zone). Using a real atlatl and dart, demonstrate how to hold the atlatl with bunny ears, load, and safely throw the dart in slow motion. Discuss the importance of using their whole body and finishing with the atlatl pointed at the target. Instruct each student to pick up their atlatl and put it on their bunny ears with the beak facing up and towards them. Make sure they are holding their atlatls correctly. Remind students the atlatl is an extension of their arm and they should not let go of it at any point. Allow each student to practice their “throw” without a dart. Confirm students' palms are facing up on their backswing and they are following through to point at their imaginary target. (2-3 min)
Level 3: Throwing darts one at a time (warm zone). Tell students they will throw darts one at a time. Remind students NO ONE may enter the hot zone to collect their darts until the instructor says it’s safe. Dart tips must always point to the target or the ground. Students should throw one at a time until the entire row finishes. Give each student one-on-one coaching. Help students notch their darts, ensure that the students’ fingers are not on top of the dart, and fix throwing errors. Remind students using an atlatl is a skill and all skills take practice to do well. When others are throwing, students can practice their level 3 throws or watch their classmates and cheer. Repeat level 4 several times. (5-10 min)
Level 4: Throwing darts all together. Students notch their dart and assume the safety stance. Have them aim their darts at the target and throw together. (2-3 min)
4) Have students place their atlatls on the ground and check that no one is still throwing. Send students to pick up their darts in the hot zone. Remind them to keep the tips of their darts on the ground. (2-3 min)
5) Use the poster to discuss how gravity, friction (wind), and human effort affected how far their darts traveled. Tell students an atlatl allows a hunter to get more force (push) with less effort or allows the dart to fly further and faster to better overcome the opposing forces. Compare to their experience throwing atlatls. Place the arrows on the poster as appropriate. The atlatl increased their human effort and helped them overcome gravity and friction. Ask students if they notice a pattern in the dart’s motion. Discuss what might happen to the trajectory if forces were removed or added (no gravity, huge wind). (3-4 min)
6) Tell students people would spend hours and hours practicing improving their skills. Remind students that today you need a license to hunt.
Fire
Essential Question: How can humans harness friction to improve their lives?
Materials: Fire Race (London, 1993); knife; bow-drill sets (one for you and one for each pair of students); at least 3 tinder nests per day; hand drill sets for each student; Gallon jug of water; fire pan; knee pads; bow drill poster: fire triangle poster.
Procedure:
1) Read Fire Race. Discuss that the story is a legend and ask why fire was important to ancient people. Discuss how we still use fire to heat our homes and cook our food today. (10 min)
2) Have students rub their hands together as hard and fast as they can. Ask students if their hands are getting warm. Tell students they are using energy to rub their hands together. Explain that most of their energy is converted into motion, but friction turns some into heat. Define friction as the resistance to force created by objects rubbing together. It acts in the opposite direction of movement and acts to slow things. Friction produces heat and sound. Explain the fire triangle: with enough fuel, heat, and oxygen, fire is created. Show students the page in the book where the character makes a fire. Discuss the hand drill and how the fire triangle applies in the picture. (2-3 min)
3) Use the book to explain the hand drill method of making fire. Demonstrate how to rub a stick between your hands, pushing down and twisting the stick. Remind students friction creates the heat that causes the fire, so the more pressure they give and the faster they go, the more likely they’ll get fire. Let students try to make fire with hand drills. Encourage them to feel the heat produced at the end of their hand drills and discuss how much more friction/heat they would need to make smoke. (5 min)
4) To increase the speed of the drill and therefore increase friction, people invented the bow drill. Show students the bow drill set and explain how the tool gets even more friction with less effort. Explain each piece and how the bow drill works; friction creates hot wood dust that will ignite and become a coal. Use the poster to show where the forces are affecting each part of the bow drill. To make a fire, the coal must be placed in a tinder nest. Use the analogy of a baby eating. When a baby is first born, it eats baby food. If you give the baby carrots, it will choke, just like the fire will choke if placed on large logs. Have students crush up some juniper bark and put it on the tinder nest. As they are working, discuss how the fire pan reduces both fire scar and the risk of the fire escaping. (2-3 min)
5) Try to demonstrate how a fire is made using the bow drill and tinder nest. While you are working, ask students if they should ever try this at home and explain why not. (5 Min)
6) Demonstrate how two people can work the fire bow together by having each student take turns working the fire bow with you. Pair students up and let them try to make fire on their own. (5min)
7) Discuss the importance of completely putting out fires. To put out a fire, one side of the fire triangle must be removed. If a fire was achieved. put water on the tinder nest. Show students how to use the back of their hand to test if any heat remains.
Eat your fruits and veggies
Essential questions: How do digging sticks reduce the amount of force needed to dig? How does a mano and metate use friction to grind corn?
Materials: Mano; metate; dried corn; ground corn container; 6 digging sticks; mano/metate poster; at least 30 clay taters; pictures of foods that were gathered or farmed; picture of real digging sticks; trowel; picture of potatoes and a sego lily; digging stick poster (showing forces acting on the tool).
Procedure:
1) Ask students where they get their food? Next, ask students where people got food a thousand years ago when there were no grocery stores. Along with hunting, people gathered plants and farmed. (2-3 min)
2) Show students the mano and metate. Tell students the ancient people farmed corn which they could dry and store for the winter. Ask if anyone eats tortillas. Explain how tortillas are made from cornmeal which is ground up corn. Show the corn and encourage them to try to smash a kernel with their bare hands or imagine what it would be like to eat it raw. Grinding foods allows them to be more portable and digestible. (2-3 min)
3) Explain “mano” means “hand” in Spanish. Show students how to hold the mano with their “kitty paws.” Give each student the opportunity to grind corn. As they work, discuss how forces effect how much effort (push and pull) a person must apply. Explain how friction works and why it grinds corn. Discuss how gravity helps hold the corn on the metate. Discuss how long it would take to grind enough corn for a meal. Tell students that as they are grinding corn, they are also grinding away the rock. Explain why grinding stones are rounded with depressions. See if they notice the sand in the meal and discuss how ancient people had dental problems, stemming from the sand in their food. (5-10 min)
4) Define tubers as starchy plant roots we can eat (i.e. potatoes or yams). The ancient people ate potatoes as well, including the Four Corners potato, a plant only found in the southwest. They also ate the sego lily, our state flower. Tell the story about how the sego lily saved the lives of the pioneers. Show students pictures of other edible tubers. Tell students digging sticks were also used to plant seeds. (3-5 min)
5) Demonstrate how the digging stick makes work easier than digging with your hands because it allows you to get more force with less effort. For thousands of years, people have used digging sticks to dig up tubers. Demonstrate how to use the digging stick. Explain that if you pull on the stem, it sometimes breaks off and the tuber gets lost underground. Have students practice using their digging sticks by digging up clay tubers. Show students where the tubers are growing and point out the pipe cleaner stems of the clay tuber plant. Remind students if they pull on the stems, stems often break. The roots, or what they eat, will stay in the ground. Encourage students to count how many tubers they find. Students must use their digging sticks. Give students 5-7 minutes to dig up and rebury tubers. Discuss how each student would share their tubers with their family(or classmates), so no one goes hungry. (5-10 min)
6) Discuss forces acting on the stick and things that affect motion of the dirt. Show photographs of both ancient and modern digging sticks and ancient digging sticks. Ask students how they are similar and different. Ask students if they can think of a similar modern-day tool (i.e. crow bar, shovel). (2-3 min)
7) Review the forces that acted on the mano/metate and digging stick using the force posters. (2-3 minutes)
Extension:
As students walk to the station, stop at a variety of plants (such as rice grass) and explain what parts are edible. Invite students to pretend to collect those parts and put them in their pretend gather baskets. At the mano and metate, have students empty their gather baskets. Show pictures of foods farmed and gathered a thousand years ago.
Stones
Essential Questions: What is the effect of the shape of the scraper on how well it cuts?
Materials: Simple stone replica scrapers; zucchini cut into long strips; plastic plates; small backpack; big water jug; dish tubs; dish towels
Prep: Cut 25 long strips of zucchini and divide them into 4 baggies/containers
Procedure:
1) Discuss what people ate during ancient times. Go on an imaginary hunt. Distribute imaginary darts and atlatls, then walk with students down the wash. Point to a spot with an imaginary animal and have students throw their darts. Ask students to help to retrieve the animal and pretend to put it in your magic game bag (a backpack containing cut up squash). (5 min)
2) Ask if students have hunted before and discuss what happens once they kill the animal. See if students know what steps are needed to turn an animal into dinner. Discuss use of the skin and ask if it would be hard to separate the meat from the skin. Show students tools to skin the animal and cut the meat. Pull out the squash from the game bag and demonstrate how to use the tool to separate the “meat” from the (rind) “skin and fur.” (2-3 min)
3) Invite students to examine the blades and think about which tools might be best to separate the skin from the meat to give them the biggest piece of leather. Tell students these tools are replicas. Show students how to hold blades. Point out the sharp side. Have students discuss how they should behave to be trusted with a sharp tool. Give instructions and let them ask questions before letting each student pick two blades. Have students predict which blade will work best. Hand each student two pieces of squash on a plate. Direct them to cut their squash in half and then skin and chop each piece with one blade. Invite students to show their work and discuss which blades created the smoothest cuts. (5-7)
4) Ask students to show and describe which tool cuts easiest. Encourage students to describe patterns they notice in the blades that slice better. Place arrows onto the poster as you discuss how gravity and friction acting on the squash and the scraper affects the effort needed. A skinnier wedge focuses your effort on a small area and reduces friction. But increasing the surface area at the edge makes cutting easier, i/e a serrated knife. Compare to types of kitchen knives used for different purposes. If students are not familiar with friction, compare sliding on ice to sliding on grass or gravel. When finished, students should put their squash in a bowl. (5-7 min)
5) Wash blades and plates. If time, encourage students to search the wash for rocks that would make good blades. (3-5 min)
Extension:
Explain how each of these points took a lot of time and skill to make. Describe how people can make these stone tools using the force of impacts. The force of a strike travels through the rock, creating a weakness; if the weakness is big enough, the rock will break. An expert knapper will know where and how hard to strike the rock to get the desired effect. (3-5 min)
Draw a Machine (adapted from O’Brien & White, 40)
Essential Question: How did the inhabitants of the Four Corners area use tools to help them make everyday tasks easier 1000 years ago?
Materials: Paper with 4 third grade style lines; one of each tool; printed questions for document camera.
Procedure:
1) Tell students people have specific needs to survive. Write on the board Food, Shelter, Water, and Heat/Fire. Ask students what humans developed to help them apply less effort to complete tasks and fulfill their needs. What tools they think people used to fulfill each need. Under each need, list the tools students mention.
Some examples are:
Food – atlatl & dart, fire drill, knives, scrapers, digging stick, mano & metate
Shelter – digging stick, axe
Heat/Fire– fire bow, fire drill
Water – digging stick, fire drill (explain they needed to fire clay pots to hold water)
3) Have each student choose a favorite tool they saw on the field trip. Have students pair share why they chose each tool. Tell them they are going to draw and write about their favorite tool. Students may choose if they want to write first or draw first. They should use arrows to point out the forces acting upon the tools and label them. Pass out paper to each student. Instruct the students they are to complete the following sentences about their tool. Place printed questions under the document camera:
1) My favorite tool is __________.
2) It is used for ______________ (food, shelter, heat, water). (Put as many as apply).
3) Forces that act on the tool are _______________ (gravity, friction, etc).
4) It is cool because _____________.
4) If time remains, encourage students to share their work.
Dunmire, W. & Tierney, G. (1997) Wild plants and native peoples of the Four Corners. Santa Fe, NM: Museum of New Mexico Press.
London, J. (1993). Fire race. San Francisco, CA: Chronicle Books.
Macaulay, D. (1988). The way things work. Boston, MA: Houghton Mifflin.
Maxwell, Amiee, How a Potato Is Fueling the Fight to Protect a National Monument, MARCH 2, 2020 https://www.atlasobscura.com/articles/four-corners-potato
O’Brien, K. & White, R. Petroglyph National Monument teachers guide. Albuquerque, NM: Petroglyph National Monument.
Wedges – Simple Machines Activities for Kids https://inventorsoftomorrow.com/2016/10/12/wedges-2/
The Physics of Chewing:http://ffden2.phys.uaf.edu/104_2012_web_projects/kjersten_williams/Page_3_Physics_of_Chewing.html
Last updated: July 26, 2022