Naked egg drop – activity – teachengineering twitter desktop view link

Student pairs experience the iterative engineering design process as they design, build, test and improve catching devices to prevent a naked egg from breaking when dropped from increasing heights. To support their design work, they learn about materials properties, energy types and conservation of energy. Acting as engineering teams, during the activity and competition they are responsible for design and construction planning within project constraints, including making engineering modifications for improvement. They carefully consider material choices to balance potentially competing requirements (such as impact-absorbing and low-cost) in the design of their prototypes. They also experience a real-world transfer of energy as the elevated egg’s gravitational potential energy turns into kinetic energy as it falls and further dissipates into other forms upon impact.

Pre- and post-activity assessments and a scoring rubric are provided. The activity scales up to district or regional egg drop competition scale. As an alternative to a ladder, detailed instructions are provided for creating a 10-foot-tall egg dropper rig.

• provide materials such as cardboard or paperboard, clean food containers, foam, tissue paper, fabric, rubber bands, packing peanuts, fiberfill, bubble wrap, cotton balls, grass and other soft and cushiony materials. Deskjet 3050a j611 series driver mac reduce the cost by salvaging these materials as much as possible and/or asking students to salvage and bring items from home.

• (optional alternative to the ladder) to improve student safety and increase the wow factor, build an egg dropper rig using the materials list and building instructions provided in the egg dropper construction and use (see figure 2). Building the device is especially recommended if a district or regional competition is planned as part of the elementary school engineering design field day unit, since its labor and material costs can be shared among many instructors/classrooms/schools. Estimated materials cost for the rig is ~$300.

• (optional) especially helpful for large competition events, make a tool to enable quick measurements of egg catcher diameters and heights before the egg drop, as a way to easily enforce the design constraints. The homemade device in figure 6 consists of a 25-cm diameter circle cut out of wood and an arm with a sliding ruler for measuring device height.

Imagine that you are at the olympics competing in the 10 meter (~30 feet) platform diving event. You’ve practiced your flawless dive countless hours and you are ready to win a gold medal. You bend your knees, your toes push against the rough surface of the platform, you take a deep breath, and you jump. Driver printer hp deskjet 2050 free download you whiz through the air, moving faster and faster for what feels like forever. You twist and turn, doing flips as you watch the faces of your supporters. Suddenly, your fingers dip into the water with your arms, shoulders, torso falling from the sky into the depths of the pool. You make the smallest of splashes. Your powerful legs kick and you surface to see all 10.0s from the judges.

Think about what type of energy you had before your jump, during your jump, and right before you hit the water. What allowed you to jump from a great height safely and confidently? What type of energy did you have at the beginning of the jump? (answer: gravitational potential energy.) what type of energy did you gain during the jump? (answer: kinetic energy.) how could you tell?

Engineering design process: A series of steps used by engineering teams to guide them as they create, evaluate and improve a design solution. Typically, the steps include: identify the need and constraints, research the problem, develop possible solutions, select a promising solution, create a prototype, test and evaluate the prototype, redesign as needed.

In classic engineering egg drop competitions, an egg gains potential energy the higher it is held above the landing surface. When the egg is released, this gravitational potential energy converts to kinetic energy, as gravity pulls the egg towards the earth’s surface. Once the egg hits the ground, all the kinetic energy (movement energy) needs to transfer somewhere. We know that energy must be transferred into different forms of energy because once the egg stops moving, it no longer has any kinetic energy.

We know by the reliable nature of our world—in this case defined as the law of conservation of energy—that energy is neither created nor destroyed, so in the case of the egg, it must be transferred to different forms of energy. Options for the egg’s dissipation of energy as it hits the pavement are sound (the splat of an egg), heat (the egg heats up from the friction of hitting the ground), and/or the continuation of kinetic energy as seen by the breaking of the shell.

But—eggs are not elastic (!) like the ball in the video, so dropped eggs will break without something to take the kinetic energy. The challenge of this activity is for students to design an egg catcher to absorb the kinetic energy and prevent a dropped egg from breaking. Figure 3. A universal testing machine that is used for tensile testing of materials to determine their elasticity.

Engineers and material scientists use machines (like the one shown in figure 3) to test materials’ stretchiness or elasticity by crushing and releasing test materials between two sensors. An egg’s shell is very brittle (not elastic) so elastic materials are the best choice to absorb a falling egg’s kinetic energy. If the egg catcher is well designed and the egg does not break, then the material absorbed enough of the egg’s energy so that the egg’s kinetic energy is not transferred to sound, heat and/or a broken shell. Desktop wallpaper size 1366×768 instead, the energy is transferred to the elastic catcher material, which might squish and then reform to its original shape, as is seen with the squash ball in the video clip.

Overall, to create a winning design, students must thoroughly understand the competition rules and scoring so that they know the constraints (requirements and limitations) of the problem well (refer to the naked egg drop rules and score sheet). This means that like real-world engineers, students must balance competing factors to be successful in this activity. Like professional engineers, they pick appropriate materials, considering the ability to dissipate kinetic energy as well as cost, reused and repurposed materials, and environmental impact of materials used. For example, while plastic foams absorb a lot of kinetic energy, they do not biodegrade quickly.

The ingenious use of materials such as packing peanuts, tissue paper, fabric, rubber bands and grass can cushion and protect an egg from damage; see the materials list for additional material ideas and refer to the rules and score sheet for prohibited materials (because they work too well!). As students follow the steps of the engineering design process (figure 4), encourage them to try different materials, different amounts of materials, and/or combinations of different materials in their egg catcher devices. Expect the designs to incorporate their knowledge of materials and the properties of those materials.

Beyond the smart use of materials, another strategy is to design and build catchers that combine the concepts of a hammock and a trampoline. In this approach, the catcher curves around the egg to hold it similar to a hammock, and is also elastic like a trampoline. Students can modify these sorts of designs by changing the height of the suspended hammock and/or the give of the springs or spring-like structures.

For the egg catcher footprint, it is best to use the largest surface area possible for increasing the likelihood of catching the dropped egg. Then, working within the constraint that the catchers must be no more than 25 cm in any direction, direct student teams to decide what shape gives them the largest surface area for aiming the egg at, as well as complying with the 25 cm rule. (A circle footprint provides the biggest surface area within this constraint.) once groups have mastered the catch from the highest possible height, have them iterate through the design process for size. Have students aim to reduce the surface area since the competition tie-breaker depends on minor diameter, which is defined with a sketch in the rules and score sheet.

• decide whether to provide students with an assortment of building materials from which to use, or break the first hour into two parts, with time in between for the teacher and/or students to acquire building materials as specified from group designs. Then, for the building component of the activity, assemble scavenged or purchased materials and/or request that students bring scavenged or purchased materials from home. Desktop backgrounds beach theme take note of the banned list of materials—items that are too effective at being shock absorbers!

• review the steps of the cyclical and iterative engineering design process (see figure 4). Tell students that as student engineers, they might begin by asking questions to understand the problem, including its criteria and constraints, then researching to learn more, then imagining ideas before making plans for how to create the best solution they can think of. Next, teams each create a prototype, test it, and change and improve the design from what they learn through testing.

• ask: identify the need and constraints. Have students read the first page of the competition rules and score sheet. As mentioned earlier, the engineering need is to design a device to catch an egg dropped from a height without the egg breaking. Make sure teams are aware of the constraints (requirements and limitations). Remind students that the egg catchers must be made of approved materials (no gels, food, powders), have all materials secured, and be less than 25 cm in any direction.

• research the problem. Have student teams independently investigate materials science and energy of motion topics. Show the class the squash ball bounce video and discuss the elasticity measuring device. Additional research might focus on inventions such as trampolines, catchers’ mitts and rock climbing pads to learn about their design approaches and materials.

• imagine: develop possible solutions. Direct student teams to brainstorm together and then design and sketch on paper their ideas for egg catcher designs. Remind students to include dimensions and materials lists. Remind them to calculate the surface area available to catch the egg of their planned devices. Encourage students to salvage materials or use materials some people consider waste (what’s in the recycling bin?). Engineers often try to incorporate underutilized materials like waste to decrease the cost and the environmental impact of their designs. Examples include saved and dried paper towels used as cushioning in the egg catcher or an empty cereal box to make the egg catcher exterior structure.

• what types of energy or energy transfer are present in the fall of the egg? (answer: prior to the drop, an elevated egg has a large amount of gravitational potential energy due to its height above the ground. When it is dropped, that the energy is transferred from potential to kinetic. Right before the egg hits the egg catcher, (nearly) all the potential energy has been converted to kinetic energy.)

The contents of this digital library curriculum were developed by the renewable energy systems opportunity for unified research collaboration and education (RESOURCE) project in the college of engineering under national science foundation GK-12 grant no. DGE 0948021. However, these contents do not necessarily represent the policies of the national science foundation, and you should not assume endorsement by the federal government.

Heartfelt thanks to travis smith, for developing, building, testing and writing instructions for the egg dropper device (figure 2). Travis also designed and made the device for quickly measuring the dropper (figure 5). Hp deskjet 3520 scanner problem you can see from figure 2, where travis is pictured in the hat and blue shirt, that he is a wealth of knowledge on engineering, geekery and fashion.