# Blow and Go Parachutes

## Learning Objectives

Through investigations, observations, and experiments, students will discover that flight occurs when the characteristics of structures take advantage of certain properties of air. They will apply their newly acquired knowledge to design and test a flying device.

## Associated Curriculum Topic

Properties of air and principles of flight

## Materials

### Each group needs:

• sheet of paper
• 4 paper strips (1’’ wide and 3’’ long)
• clay/PlayDoh
• 2 drinking straws (one jumbo and one regular size)
• plastic grocery bag
• scissors

## Introduction/Motivation

In this activity, students will investigate the lift (upward force) that a canopy can provide for a falling object: students will witness first hand the effects that a parachute or canopy can play on a skydiver. When a skydiver falls toward the ground, he/she accelerates due to the force of gravity. As they fall, the force of gravity acting downwards is much larger than the upward force of air resistance. Once the skydiver is close to the ground, he/she would like to reduce their falling speed in order to land safely, which can be done by releasing their parachute. Once the parachute is released, the skydiver increases the amount or area exposed to the air rushing by them as they fall towards the ground. This increase in area causes the upward air resistance force to become much larger and the skydiver reduces their acceleration, allowing them to reach the ground more safely.

## Procedure

• with a quarter sheet of paper, roll a cone shape so that the opening of the cone is approximately 1 ½ inches across, use tape to secure the cone
• trim the cone opening with scissors so that the base of the cone is even
• divide the clay into 4 balls, making sure that 1 of the balls is approximately twice as large as the other 3
• using a piece of tape, seal off one of the ends of the jumbo straw
• press the sealed end of the jumbo straw into the largest ball of clay
• use the clay on the end of the jumbo straw to attach the straw to the inside of the cone ensuring that the open end of the straw faces outward
• position the 3 smallest pieces of clay along the inside of the cone opening at equal spacing (this will ensure that the parachuting person does not flip over while falling towards the ground)
• tape on folded paper strips as arms and legs of your parachuting person
• using markers, decorate your parachuting person
• Slide the smaller drinking straw into the jumbo straw
• Blow into the drinking straw and watch your parachuting person fly into the air and fall back to the ground (record what you observe on your worksheet)
• cut an 8-inch square out of the plastic bag to make a canopy
• cut four 8 inch long pieces of thread; use tape and the thread to attach each of the corners of the plastic canopy to the point of the cone
• lay the plastic canopy on the cone and slide the drinking straw into the jumbo straw
• blow again through the drinking straw and note the difference in how fast your parachuting person falls to the floor

### Trouble shooting:

• if you’re having trouble launching the skydiver, you might want to trim the length of the jumbo straw
• if your skydiver is flipping over, add more clay balls to the inside of the opening of the cone
• if the canopy does not open, try changing the size of the canopy

## Investigating Questions

• What is the purpose of the parachute on a skydiver?
• What forces act on a skydiver?
• What force does the canopy apply on the skydiver?
• What would happen if we made the canopy smaller?
• What would happen if we made the canopy larger?