# Hands-on Activity: Design a Parachute

### Summary

After a discussion about what a parachute is and how it works, students create parachutes using different materials that they think will work best. They test their designs, and then contribute to a class discussion (and possible journal writing) to report which paper materials worked best.

### Engineering Connection

Aerodynamics and fluid flow concepts are used by engineers to design planes, parachutes and ships. Accounting for drag is an important aspect of these designs; engineers redesign the shape and materials used to get better results.

### Educational Standards

•   Common Core State Standards for Mathematics: Math
•   International Technology and Engineering Educators Association: Technology
•   Massachusetts: Science
•   Next Generation Science Standards: Science

### Learning Objectives

• Techniques for designing a parachute that falls slowly.
• How to determine which type of material works best by testing different options.
• How air resistance plays a role in flying.

### Materials List

• tissue paper
• napkins
• construction paper
• newspaper
• paper towels
• string
• tape
• weights (such as washers)

### Introduction/Motivation

What is the purpose of a parachute? What is the role of a parachute in skydiving?
Imagine you are jumping out of a plane 10,000 feet in the air. What type of material would you want your parachute to be made of and what size would you want it to be?
The design of a parachute is very important, especially in an extreme sport such as skydiving because someone's life is dependent on the parachute functioning correctly. Engineers thoroughly test the materials and designs of parachutes to ensure that they open as intended and reliably, and are strong enough to withstand the air resistance needed to slow skydivers to safe landing speeds.

### Procedure

Background

A parachute is an umbrella-shaped device of light fabric used especially for making a safe jump from aircraft. Due to the resistance of air, a drag force acts on a falling body (parachute) to slow down its motion. Without air resistance, or drag, objects would continue to increase speed until they hit the ground. The larger the object, the greater its air resistance. Parachutes use a large canopy to increase air resistance. This gives a slow fall and a soft landing.
Recommended resources:
A history of parachutes, plus good pictures: http://www.parachutehistory.com/
Explanation of free fall and air resistance with diagrams (Newton's second law): http://www.physicsclassroom.com/class/newtlaws/Lesson-3/Free-Fall-and-Air-Resistance
Explanation of forces on a falling object with air resistance: http://www.grc.nasa.gov/WWW/K-12/airplane/falling.html

With the Students

1. Gather materials.
2. Discuss with the class what a parachute is and how it works.
3. Have student teams brainstorm characteristics of a good parachute, document their thoughts and sketch their design before construction begins.
Parachute Construction
1. Cut a circle (or other shape) from the chosen paper. Make a hole in the center of the shape.
2. Cut six pieces of equal length string and tape them at equal distances around the edge of the shape.
3. Tape the other ends of the string to a weight.
4. Test the parachute. Go outside and drop it from a specific height to see if it flies slowly and lands gently. Record your observations.
5. As time permits, repeat the process, modifying the variables of canopy material and shape. Record your observations.
6. Lead a class discussion to compare results and draw conclusions.
7. Assign students to recap their findings as a written journal entry that documents their design details and results, and answers the Investigating Questions..

### Investigating Questions

• Direct students to calculate the area of their parachutes (A=πr2). Create a graph on the board showing area vs. drop time. Then, as a class, discuss how the area of the parachute affects its flight.
• What type of paper is the best material to make a parachute? Why?
• What materials did not work well? Why?
• What changes could you make to improve your design?

### Activity Extensions

Using the paper material that worked the best, do the same activity testing the parachute size. Have students test circles with different radii to find the optimal size.
Try parachutes with and without holes in the top, and different-sized holes.
Make parachutes using different materials, such as plastics, cotton and nylon.
Hold a competition to find a design that can land a toy vehicle most gently.