Constructing a Marshmallow Catapult

Literature Review

Engineering design activities can be a powerful entry point into science learning. Attempting a design-build project, students use creativity within their project to tackle the problem (Wicklein, 2006). As students develop an understanding of design-build projects, teachers can challenge them with an application of a local community based engineering issue to create a relevant issue that students can begin to solve. Engineering design-build projects, “hands-on” or “learning by doing,” is grounded in constructivist theory (Fortus, Krajcikb, Dershimerb, Marx, & Mamlok-Naamand, 2005) that is shown to improve student achievement in higher level cognitive tasks, such as scientific processes and mathematical problem solving (Satchwell & Loepp, 2002). Current research indicates that when students are given a project-based task, their interest in STEM can be increased because it requires students to solve authentic problems based on real issues (Fortus et al., 2005). Teachers today are challenged in many ways, from administrative tasks to having students reach goals on the state mandated test scores; this form of instruction provides an engaging methodology that allows the curriculum to be relevant while teaching important skills to your students. Students will be engaged in problem-solving, using critical thinking skills, collaboration, communication, and creativity, all while learning the content you are asked to teach your students. Art and engineering embody creativity by integrating the physics of nature while using the art to creatively design the most effective object to solve a problem or solve an issue. Students will experience, or be introduced to, STEM careers while being challenged to solve a problem or issue.

Figure 1.

Engineering design triangle: Next generation science standards, grades 9-12

Content Information

This engineering design-build project will integrate many content areas. Students are first asked to research catapults throughout history and identify effective designs. Students will use good, reliable resources from the internet while identifying quality search terms to help seek the information necessary to design an effective catapult. Students will also identify the time period throughout history when catapults were used and for what purpose. Some students may ponder how this device could be used today. As the students continue designing their catapult, they will need to collaborate and communicate with other group members, sharing their thoughts and ideas.

Mathematics will be an important integration in this activity. Students will investigate many variables, and perhaps identify many more during this investigation. The first variable that students will most likely want to investigate is the angle of launch. If the angle is too great, the projectile will go too high which will result in a shorter distance launched. On the other hand, an angle too low may overshoot the target. It is important to allow students time to test various angles. Figure 2 below explains the angle of launch. Another variable that could be tested is the rubber band resistance. If possible, provide various tensions of rubber bands, which will affect the speed of the projectile. The greater the tension, the greater the speed of the projectile. Another variable that the students can experiment with is the length of the catapult from the target. One final variable, for student exploration, is the length of the catapult launching arm. How will that change the accuracy along with varying the angle of the launch? Encourage your students to explore all these variables and create a data table to collect all these changes in their variables.

Figure 2.

Angle of launch using the laws of trigonometry which relate the initial velocity to the maximum height and distance of the projectile. V= velocity and X is the launch angle

A general summary of the content covered with this activity is: