Egg Catapult Engineering

In order to assess and activate prior knowledge, ask the following questions:

• What is energy?
• What is potential energy?
• What is stored energy?
• What happens when force is acted upon an object? Does it move or does it stay still?

1. Based on the students answers to these questions, determine how deep to explain these concepts. Display the definition of energy, potential energy, and stored energy on the board and create a small discussion around the words.
2. Have students line up to go outside for an activity.
3. Once outside, the teacher will place a piece of tape on the ground to make a line. Students will stand behind the line and kick a soccer ball. Each student will have a turn and will mark where the soccer ball landed after they kicked it. The students notice the distance that the ball went based off of the energy that they used to move the soccer ball from sitting still to another location.
4. The students will go back inside after this. Once the students are inside the teacher will separate the students into groups of two to create catapults. They will be given plastic spoons, rubber bands, paper clips, assorted sized popsicle sticks, plastic eggs, and a measurement tool (ruler, yard stick, or measuring tape).
5. The teacher will provide an example of what a catapult could look like but students will be encouraged to create their own catapult using their creativity.
6. Pose the Problem on the board:

Problem: Create a catapult that catapults a plastic egg the farthest. Try to figure out what way you can create the most efficient catapult to use the most potential energy that then turns energy in motion. Explain that engineers that use catapults are engineers who are interested in all things to know about energy!

     7. Students will create their catapult and then test their predictions by catapulting their items one at a time.
     8. Students will record their data using the measurement tool(s) provided.
     9. After this data is recorded, students will come together and discuss which catapult flung the egg the farthest and why they think that this happened.
    10. Students will then be given a second round of materials and told to create another catapult. Encourage them to create a different catapult than the first to see which one projects the eggs the farthest.
    11. After the students have created their second catapult, they will then predict which object will go the farthest and explain why they believe that that item will go the farthest.
    12. Students will record their data and compare their data, with their partner, about which catapult worked the best and why they think that that specific catapult worked the best.
    13. Students will then come together with the teacher and discuss their results.

Guided Questions for discussion:

• Which catapult worked the best?  Why do you think that?
• Which designs didn’t work well at all? Why do you think that?
• Explain how potential/stored energy is used in this experiment.
• Explain how your force can determine the distance.

Extension: Can you design a different catapult using the same materials but in a different way to catapult the items further?

Differentiation: Provide teacher assistance as needed when constructing the catapult.

When you pull back the popsicle stick, you are building up your potential/stored energy by bending it back.  As you release your egg, that energy that was one not moving is now in motion because of the force that acted upon it.  If the students can explain this to the teacher, you will know that they have achieved the lesson objective.  The teacher will be able to understand whether or not students have understood this concept based off of the discussion that the students have throughout the activity. 

The teacher will ask the students guiding questions and the answers that the students give the teacher will help the teacher determine if the students grasped the concept. This assessment style is formative because the teacher is assessing the students’ understanding throughout the entire lesson by the way they participate in engineering the catapults and how they analyze their results.