# Making Marshmallow Catapults

1. Overview
2. Introduction
3. Materials
4. Instructions
5. Activity Questions
6. Assessment
7. Suggestions for Expanding the Activity
8. Learning Standards

## Overview

During this hands-on activity, students will be able to make their own marshmallow catapults. This activity demonstrates concepts related to levers, a simple machine. This activity is simple and inexpensive, yet it provides endless possibilities for lesson expansion and fullfillment of learning standards.

## Introduction

#### Related Concepts

The concept that will be focused on for this lesson is the lever, a simple machine.

#### Background Information

When you push or pull on an object, you are exerting a force. People exert this force to move objects from one place to another. This exerted force is called work.

There are six simple machines for performing work. The lever is one of these simple machines. A lever consists of a plank that is free at both ends, and a steady object on which the plank can rest. The object that does not move is called the fulcrum. The object that one is trying to move is called the load. The distance from the load to the fulcrum is called the effort arm.

In this activity, students will build a lever that will move the load, which is the marshmallow.

#### Getting the Lesson Started!

Here are some potential discussion questions:

1. What is a simple machine?
2. What is a lever?
3. What kind of objects do you think of when you hear the word lever?

## Materials

• 2 erasers
• 1 mousetrap
• 2 popsicle sticks
• 1 rubber band
• 1 spoon
• duct tape

## Instructions

1. Pull back the mousetrap lever. Place the rubber band around the base of the mousetrap and the lever to hold the lever in place.
2. Fasten one of the erasers to the mousetrap using a piece of duct tape. The long end of the eraser should be up against the fulcrum of the mousetrap.
3. Tape a second eraser on top of the first eraser so that the second eraser is slightly over the fulcrum. Place tape around both of the erasers.
4. Carefully remove the rubber band from the lever, and slowly bring it to stand next to the erasers.
5. Tape one of the popsicle sticks to the lever so that it is perpendicular with the lever. This will support the catapult arm.
6. Tape another popsicle stick to the lever so that it is parallel with the lever. This will extend the arm of your catapult.
7. On the end of the second popsicle stick, rubber band or tape your plastic spoon.
8. Your catapult is ready for use! When using the catapult, always make sure to hold down the base.

## Activity Questions

1. If the effort arm of a lever is shortened, what happens to the force needed to make the load move?
2. Levers are all around us. List two levers that people use all the time.
3. True or False. Using a a lever to lift a load is easier than lifting it alone.
4. What is a fulcrum?
5. Explain what force is.
6. What kind of lever would you see on a car?

## Assessment

#### Assessment Background

Our assessment methods were the same for Illinois and National Standards.

Our assessment methods were the same and for Early and Late Elementary School students. What changed was the level of the questions asked and the discussion.

#### During the Lesson

The participants used inquiry strategies to determine how to build their marshmallow catapults. Participants discussed how successful other materials would be for the catapult. Throughout the lesson, the participants discussed how catapults are used in science, technology, and society.

#### At the End of the Lesson

At the conclusion of the lesson, a discussion was held to determine the level of participant understanding of how a catapult is built and how it works. The discussion also encouraged students to think critically about how this device can be used in society.

Here is a sample of questions from that discussion:

• What are levers used in society?
• What types of levers are around us?
• What is the realtionship between force and distance?
• How can force be measured?

Each of the children who participated in the lesson was able to answer these questions at his/her own level.

## Suggestions for Expanding the Activity

Math can be integrated into the lesson by having the students measure the distance that the objects are catapulted. Participants may want to vary the objects that are catapulted. From this, participants may make a connection between mass of the object and the distance it is catapulted.

Before the exercise, participants can first build a simple lever to help them understand the concept. Participants can make a simple lever by arranging a book and a ruler near the edge of a desk as shown below:

Let the ruler hang over the edge of the desk about 8 inches. Then apply force to the end of the ruler to lift the book.

Now let the ruler hang over the edge of the desk by 4 inches and apply force. In which situation is less force required?

## Illinois State Learning Standards that Apply to this Lesson

The following standards are from the Illinois Learning Standards, adopted by the Illinois State Board of Education on July 25, 1997. Take a look at the complete Illinois Learning Standards for Science, and for English/Language Arts.