## Overview

Students compare the drawings they made in Lesson 4. They discuss what makes a clear drawing. The teacher introduces concepts of  stored energy, energy transformations, and friction as evidenced in wind-ups, then helps students discuss “how a wind-up works.   Students write a troubleshooting guide.

• Chart of Issues from Lesson 2.
• Troubleshooting Chart from Lesson 3.
• Chart paper drawings of a wind-up from “bird’s – eye view” and end view.
• Photo copy the worksheet: “Wind-up Troubleshooting guide”.

## Materials

• Students’ wind-up drawings from Lesson 4.

## Procedure

1.      Gallery walk:  Students post their wind-up drawings around the room, then view one-another’s drawings. They make note of

• What makes it easy to understand how the wind-up was made?
• What makes it difficult to understand how the wind-up was made?

2.      Class meeting: Students share their observations of what made drawings easy or difficult to understand. Two things that usually make drawings more understandable are

• Label the parts of the wind-up
• Draw the wind-up from different points of view

Introduce the notion of “point of view” by asking what the wind-up would look like from the top and the end. An overhead projector or an ELMO can be used to show the differences in these two points of view. Show your own drawing of a top and end view of your wind-up, then have students make a “quick sketch” of their own wind-up from both top and end views.

3.      Review energy concepts: In Lesson 2 energy concepts of potential energy , kinetic energy, elastic energy, energy of motion, and stored energy were introduced, and demonstrated, in the context of the wind-up.  Quickly reinforce these concepts, again using a wind-up.  Now focus on energy storage and transformations: energy is transformed from the energy of motion (or kinetic energy) to elastic energy (or potential energy).  This elastic energy is stored in the twisted rubber band, waiting to be released and transformed back to kinetic energy.

4.      How does a wind-up work?: Ask students to describe, step by step, how a wind-up works, beginning with the input of the student's energy that turns the stick and rubber band to the output of the moving wind-up.   These steps are described in detail at the end of this lesson.

5.      Troubleshooting guide:  Display the chart of Issues from Lesson 2 and the Troubleshooting Chart from Lesson 3.  List the kinds of issues students had making their second wind-up.  Distribute the worksheet. Based on the example you have just shown, ask each student to create a Troubleshooting Guide showing how to deal with each issue they have resolved.  Note that there could be two causes and two fixes for one issue.

6.      Outcomes

• Students understand energy concepts and how they are involved in how their wind-up works.
• Students create a Troubleshooting Guide.
• Word wall words: point of view, bird’s eye view, end view, transformation of energy, input, output.