Day 3: Parachute Failure Points & Improvements
Lesson 9 of 19
Objective: SWBAT use the Engineering Method to construct parachutes.
Inquiry Based Instructional Model
To intertwine scientific knowledge and practices and to empower students to learn through exploration, it is essential for scientific inquiry to be embedded in science education. While there are many types of inquiry-based models, one model that I've grown to appreciate and use is called the FERA Learning Cycle, developed by the National Science Resources Center (NSRC):
A framework for implementation can be found here.
I absolutely love how the Center for Inquiry Science at the Institute for Systems Biology explains that this is "not a locked-step method" but "rather a cyclical process," meaning that some lessons may start off at the focus phase while others may begin at the explore phase.
Finally, an amazing article found at Edudemic.com, How Inquiry-Based Learning Works with STEM, very clearly outlines how inquiry based learning "paves the way for effective learning in science" and supports College and Career Readiness, particularly in the area of STEM career choices.
In this unit, students will develop an understanding of gravity while focusing heavily on the 5th Grade Engineering and Design standards. In the first few lessons students will explore the relationships between gravity, weight, and mass. Then, students will apply their understanding of gravity to engineer and design parachutes and roller coasters.
Summary of Lesson
Today, I will open the lesson by reviewing the concepts of gravity and air resistance. We will also review the criteria for engineering their parachutes. Student science teams will then finish constructing and testing their parachute designs while documenting failure points and improvements. Finally, students will present their parachute designs to the class.
Next Generation Science Standards
This lesson will address the following NGSS Standard(s):
5-PS2-1. Support an argument that the gravitational force exerted by Earth on objects is directed down.
3-5-ETS1-1. Define a simple design problem reflecting a need or a want that includes specified criteria for success and constraints on materials, time, or cost.
3-5-ETS1-2. Generate and compare multiple possible solutions to a problem based on how well each is likely to meet the criteria and constraints of the problem.
3-5-ETS1-3. Plan and carry out fair tests in which variables are controlled and failure points are considered to identify aspects of a model or prototype that can be improved.
Scientific & Engineering Practices
For this lesson, students are engaged in Science & Engineering Practices 2.
Science & Engineering Practice 2: Developing and Using Models - Students will be constructing models of parachutes and taking into consideration constraints on materials.
To relate content across disciplinary content, during this lesson I focus on Crosscutting Concept 4.
Crosscutting Concept 4: Systems and System Models - Students will make an explicit model of a parachute system using the available materials. They will also determine which components are most important in the parachute system.
Disciplinary Core Ideas
In addition, this lesson also aligns with the Disciplinary Core Ideas:
PS2.B. Types of Interactions: The gravitational force of Earth acting on an object near Earth’s surface pulls that object toward the planet’s center. (5-PS2-1)
ETS1.A. Defining and Delimiting Engineering Problems: Possible solutions to a problem are limited by available materials and resources (constraints). The success of a designed solution is determined by considering the desired features of a solution (criteria). Different proposals for solutions can be compared on the basis of how well each one meets the specified criteria for success or how well each takes the constraints into account. (3-5-ETS1-1)
ETS1.B. Developing Possible Solutions: Research on a problem should be carried out before beginning to design a solution. Testing a solution involves investigating how well it performs under a range of likely conditions. (3-5-ETS1-S2) At whatever stage, communicating with peers about proposed solutions is an important part of the design process, and shared ideas can lead to improved designs. (3-5-ETS1-2) Tests are often designed to identify failure points or difficulties, which suggest the elements of the design that need to be improved. (3-5-ETS1-3)
ETS1.C. Optimizing the Design Solution: Different solutions need to be tested in order to determine which of them best solves the problem, given the criteria and the constraints. (3-5-ETS1-3)
Choosing Science Teams
With science, it is often difficult to find a balance between providing students with as many hands-on experiences as possible, having plenty of science materials, and offering students a collaborative setting to solve problems. Any time groups have four or more students, the opportunities for individual students to speak and take part in the exploration process decreases. With groups of two, I often struggle to find enough science materials to go around. So this year, I chose to place students in teams of three! Picking science teams is always easy as I already have students placed in desk groups based upon behavior, abilities, and communication skills. Each desk group has about six kids, so I simply divide this larger group in half.
Gathering Supplies & Assigning Roles
To encourage a smooth running classroom, I ask students to decide who is a 1, 2, or 3 in their groups of three students (without talking). In no time, each student has a number in the air. I'll then ask the "threes" to get certain supplies, "ones" to grab their computers, and "twos" to hand out papers (or whatever is needed for the lesson). This management strategy has proven to be effective when cleaning up and returning supplies as well!
Lesson Introduction & Goal
I review our learning goal: I can use the Engineering Method to construct a parachute.
We review the following concepts:
Gravity is a pulling force. The gravitational force of Earth pulls a skydiver (or washer... or any other object near Earth's surface) toward the planet's center. As gravity pulls on falling objects, the objects gain speed (or accelerate).
Air resistance is a pushing force (also called a drag force) that counteracts the force of gravity. When parachutes fall to Earth, air resistance pushes back against them. This is similar to walking in a swimming pool. If there isn't any water, you are able to walk quickly and easily. However, if the swimming pool is full of water, the water pushes against your body. As a parachute falls to Earth, the air slows the parachute down, depending on the surface area of parachute.
Parachutes with more air resistance will cause a skydiver to fall slower. We discuss which parachute will fall slower to Earth: a large parachute or a small parachute? (As long as both parachutes are built the exact same way, the larger parachute will fall to the Earth slower because there is more air resistance.)
I want to encourage students to find more ways to increase the air resistance of their parachutes, so I show this inspiring video. I'm hoping students will notice that they can also add streamers to increase the drag. I also like that this video reinforces and revisits major science concepts having to do with gravity.
The Engineering Method
Referring to The Engineering Method posters displayed on our science wall, we review how engineers use the design process to create solutions to problems. Today, we are going to finish testing prototypes, identifying failure points, and improving the design. Then, for the last 30 minutes, each group will be given time to Communicate Results (this is the final step to the Engineering Method).
Let's go over the criteria for success:
- The parachute and washer must be dropped at 2 meters off the floor. (We change this to 1.5 meters or 150 centimeters as students have a hard time reaching above 2 meters!)
- The washer must hit the target.
- The parachute must transport the washer to the ground as slowly as possible.
We also review the material constraints of this engineering challenge:
- 5 napkins
- 6 straws
- 2 pieces of paper (11"x8.5")
- 1 yard of string
- 1 plastic cup
- 5 paper clips
- 50 square inches of cardboard
- plastic shopping bag
- 2 coffee filters
- one full sheet of newspaper
Identifying Failure Points
Yesterday, students began thinking about failure points that lead to specific improvements to the design. Today, each team of students will be responsible for documenting at least one failure point and improvement in a shared Google Document, Identifying Failure Points. Students will take a snapshot of the failure point and include a short explanation of the failure. Then, students will take a snapshot of the improvement. Finally, students will record the results of the improvement. At the end of today's science lesson, students will not only present their parachutes, but they will also share a failure point and improvement.
As a side note, I chose one student per group to share the document with. Then, this student copied the document, making it their own. All three students on the team contributed to the document, but only one computer was used per team. This helped save desk space for parachute building!
Students get their parachute supply boxes, two meter sticks, a stop watch, and a Target. While testing their parachutes, one student stands on a chair to release the parachute while another student holds the two meter sticks, one on top of the other. The third student is in charge of monitoring the time it takes for the washer to drop to the ground and hit the target.
For the next 30 minutes, students continue building and testing their parachute prototype while documenting failure points and improvements. I ask students to also begin preparing for their class presentations. Each team's presentation will include:
- An explanation of ONE failure point and improvement that led to the greatest result. (For this part, students will share their Identifying Failure Points Google Document with me and I will project their work for the class to see).
- A demonstration of the parachute being dropped on the target two times.
Monitoring Student Understanding
Once students continue testing and improving their parachute protocols, I conference with every group. My goal is to support students by asking guiding questions (listed below). I also want to encourage students to engage in Science & Engineering Practice 7: Engaging in Argument from Evidence.
- What patterns have you noticed?
- Why do you suppose ____?
- What have you found so far?
- Has your thinking changed?
- What evidence do you have?
- How did you decide _____?
- Has your thinking changed?
- What conclusion can you draw about ____?
- What failure points are you noticing?
- What improvements have you made?
- What were the results of the improvements?
Here, Square Canopy, a group uses their understanding of air resistance and their research to construct their parachute prototype. I love seeing how flexible this group is when it comes to trying a new approach. This is so important as an engineer!
When conferencing with this group, Identifying Failure Points, the students share a failure point and how it helped them identify a way to improve their design. It's great to see that they are approaching the design process using critical thinking.
Here's an example of student work during this time: Blue Group's Failure Points. Most students were so busy creating their design that it was hard to take the time to capture pictures and document failure points! Perhaps if this lesson was extended and if students had more time, they would be able to produce more! If only we had more time!
Reflect & Apply
Although it's tough to stop the engineering process, I invite teams to return materials, share their Google Documents with me, and to meet at the front of the classroom with their parachutes. I ask student volunteers to be in charge of setting up a chair, holding of meter sticks, setting up a target, and managing a stop watch.
Failure Point & Improvement
First, each team of students present how they improved their design based on the identification of a failure point. I project each group's Google Document during this time to help the class visualize the design process of each team. It was great to hear students making connections, "We observed that too!" or "That's what we wanted to try next!"
After a team shares their failure point and improvement, they provide the class with a demonstration of their parachute falling toward the target on the floor. Each team drops their parachute up to two times.
Here are a couple examples of group presentations during this time: