## Warm Up: Exit Slip Discussion and Newton's Third Law

Distribute (or provide access to) students’ Exit Slip responses from Lesson 3 and review the responses as a class.

- Explain how you used the relationship among force, mass, and acceleration while playing
*Motion Force*.Answers will vary, but students should understand that increasing the force on an object increases its acceleration. Increasing an object’s mass decreases its acceleration. - The formula
is part of Newton’s Second Law of Motion. If you know the mass and acceleration of an object, you can find the amount of force acting on the object. How would you find the mass of an object if you know its acceleration and the amount of force acting on it?*F = m ͯ a*Rearrange the formula and divide force by acceleration to solve for m.

Divide students into pairs and give each student pair a set of Action-Reaction Cards. Have students work together to determine the action and reaction forces shown on each card. Do not provide any further explanations at this point. Encourage students to do their best.

Once students have had several minutes to analyze the cards, discuss what they determined regarding action and reaction forces. Lead into a discussion of Newton’s Third Law of Motion: for every action, there is an equal and opposite reaction.

## GAME PLAY!

Have students continue their last *Motion Force* game with their partners for approximately 30 minutes. However, if enough computers are available, students can start a new game and play individually.

- Allow students to play uninterrupted, but ask them to think about how they might tell their own story about forces and motion.
- Encourage students to think about using illustrations and their own words to describe how an object’s motion is affected by forces, and how Newton’s laws apply to the situation.

## Writing Activity: Newton's Laws in Action

Instruct students to read the description of the writing activity in the *Student Guide*. Distribute the colored pencils and/or markers, construction paper, scissors, stapler, and the Illustrated Story Scoring Rubric. Review the scoring rubric with students before they start writing their stories.

Let students know that they should create a storybook using the construction paper, and that the story should focus on Newton’s Laws of Motion. Students can be creative, but they should include scientifically accurate information that relates to the content of the unit.

Once all students have finished, have them take turns sharing their stories with the class. Encourage classmates to offer constructive feedback, perhaps by giving extra-credit points to any student who participates in giving feedback.