In this unit, we will learn about forces – a push or a pull on an object – and how forces can cause an object to move, change direction or speed, or stop. We will be exploring the scientific laws that describe the motion of objects and conducting experiments to predict and demonstrate the motion of objects.

Over the course of this unit, students will also be completing an engineering project to design and build a racquetball launcher. At the end of the unit students’ launchers will compete based on the accuracy and distance with which they can launch. This will allow our students to apply and demonstrate what they have learned about forces and motion in this unit. Project work days will be designated during the unit, so everyone should be able to complete most of their work on this project during our class time. Complete project requirements, can be found in the handouts and resources section of lesson 1 for this unit.

### PowerPoint Presentations

**Lesson 1: Balanced and Unbalanced Forces** In lesson 1, we will introduce the unit by discussing forces – pushes or pulls on objects. We will also be exploring the concepts of balanced and unbalanced forces. All objects, whether at rest or in motion, have forces acting upon them. These can be contact forces – pushes or pulls caused by other objects, or non-contact forces – invisible forces such as magnetism and gravity. When the forces acting on an object cancel one another out, or are balanced, the object will not move. In this case we say that the object is at rest. When forces acting on an object do not balance, however, the object will move. We will also be discussing and examining real-world examples of both balanced and unbalanced forces. **Download PDF Notes**

**Lesson 2: What is Motion?** In lesson 2, we will explore the concept of motion, which simply put is the act of moving. We can observe motion by observing a change in an object’s position. More than 300 years ago, Isaac Newton wrote *Mathematical **Principles of Natural **Philosophy*, which formulated three scientific laws that describe motion. We will introduce Newton’s laws of motion in this lesson, but we will be looking at each in more detail throughout the remainder of the unit. These laws include important concepts such as inertia, acceleration, and force pairs. By understanding and applying these fundamental concepts, scientists are able to describe and explain motion of objects of all sizes, not just on Earth, but throughout the universe. **Download PDF Notes**

**Lesson 3: Inertia – Newton’s First Law** In lesson 3, we will be discussing Newton’s First Law of Motion. Also known as the Law of Inertia, Newton’s First Law of Motion states that an object in motion will remain in motion and an object at rest will remain at rest unless acted on by an outside force. A ball at rest on a table will remain there until a push rolls it off the edge. As the ball falls, it will continue falling until it hits the ground. On Earth the forces of gravity and friction affect the inertia of objects. a rolling ball will eventually come to a stop because of the downward pull of Earth’s gravity and its contact with the ground. We will further investigate how these forces work to affect the motion of objects. **Download PDF Notes**

**Lesson 4: Acceleration – Newton’s Second Law** In lesson 4, we will be exploring Newton’s Second Law of Motion. This scientific law states that an object’s acceleration is directly related to applied force and inversely related to the object’s mass. This means that a greater force applied to an object will result in greater acceleration; however, an object with a larger mass will require a greater force to accelerate it. In this lesson, we will also examine velocity – a measurement of an object’s speed and direction. We will also be conducting experiments to observe Newton’s Second Law of motion. Using a variety of acceleration graphs, we will be able to compare and describe the acceleration and velocity of a variety of objects. **Download PDF**** Notes**

**Lesson 5: Action and Reaction – Newton’s Third Law** Lesson 5, the final lesson of this unit, looks at Newton’s Third Law of Motion. This final scientific law states that for every action, there is an equal and opposite reaction. This essentially means that forces occur in pairs. A force acting on an object in a certain direction will result in an opposing force, or a force in the opposite direction. This important concept can be demonstrated or observed by hitting a baseball, launching a rocket, or simply by jumping. In this lesson we will look at other ways to demonstrate Newton’s Third Law of Motion. We will also be using force diagrams to explore practical applications of this important concept. **Download PDF**** Notes**

### Resources and Other Documentation

** Engineering Challenge: Racquetball Launcher **For our forces and motion project, students will be challenged to design and build a device that will launch a racquetball at a target. This device must use mechanical energy to accurately launch the ball, and students will compete to determine the most effective design. Awards will be given to the most accurate design at a distance of ten feet and for the design that is able to hit the target from the greatest distance. Weekly work days during out science classes will be announced each week so that most of the work for this project can be completed at school. A variety of construction materials and tools will be provided in class, but students may also choose to bring some materials from home. For full details and requirements for this project, refer to the Engineering Challenge: Racquetball Launcher PDF.

** Unit 5 Guided Notes** The guided notes for each unit provide students with a printable copy of notes summarizing the content from each class. Blanks are inserted into the notes where key facts or content should appear. As information is covered during class, students should write missing content into the blanks to complete the guided notes. These guided notes may also be used as a review tool for unit tests. Students may print a copy of the guided notes and fill in the missing content. This can be checked using the complete PDF notes for each lesson.