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READING Lesson 1: Forces and Motion ENGAGE EXPLORE EXPLAIN ELABORATE EVALUATE CLOSE READING Notes Gravity and Friction Gravity Even if you are not moving, a force is acting on you right now. This force acts on you all the time. It is pulling you and Earth together. The name of this force is gravity. Gravity is a noncontact force that acts over a distance and pulls all objects toward each other. The pull of gravity between two objects depends on two factors. One is the amount of material in the objects. The other is the distance between the objects. Objects with more weight or mass have a stronger gravitational pull. For instance, the mass of Earth is huge. Its strong gravity pulls on smaller objects near it, holding everything around us to Earth’s surface. Gravity pulls toward the center of Earth. This force is what keeps your feet on the ground. Gravity is also stronger when objects are closer together. The Moon is less massive than Earth, so its pull is weaker. But you cannot sense the gravity of the Moon because it is also far away. Inspect Read the passage Gravity and Friction . Underline text that explains how gravity and friction effect objects. Find Evidence Reread the text and see if you can divide it into parts. What parts would you have? Write your answers in the Notes column. Copyright © McGraw-Hill Education Gravity pulls the apple to the ground. one part about gravity and one part about friction 14 EXPLAIN Module: Energy and Motion 005_022_NA_SCI_SE_G4_MAL1U1_699632.indd 14 21/12/18 8:18 PM 30 min small groups Lesson Vocabulary friction Tell students the word friction comes from the Latin word frictionem , which means “a rubbing or rubbing down.” Friction is a force that resists motion between two surfaces that rub against each other. Inspect Read Tell students they will read this passage to learn about the effects of gravity and friction. After reading, students will answer the question: “What effects do gravity and friction have on a roller coaster?” Remind students to take notes and circle any confusing words or phrases. ASK: In just three sentences, summarize the text. Sample answer: Gravity and friction are two forces that can act on an object. Gravity is a non contact force that pulls objects towards each other. Friction is a contact force that slows or stops objects from moving. Lesson Vocabulary Confirm students’ understanding of the content and have a brief class discussion of the word. friction Also comes from the Latin word frictionem meaning “a rubbing or rubbing down.” Find Evidence Reread Have students reread the text using Think-Pair-Share in a small group. Listen to students as they share to determine whether they understand the overall meaning. Students may discuss the words they underlined as well as any words they circled that confused them. ASK: Describe the forces that are acting on someone who is sitting on a chair. Sample answer: There are at least two forces acting on a person who is sitting. Gravity is pushing down, and there is an opposite but equal force of the chair that is pushing up. GO ONLINE Close Reading: Gravity and Friction INTERACTIVE PRESENTATION Differentiated Instruction AL Have students use lesson vocabulary to describe objects in the classroom. Be sure to provide some examples that move, such as sliding a chair, rolling a pencil, and so on. OL Have students work in small groups to act out the meanings of and provide examples for inertia , gravity , and friction . BL Have students use arrows in a diagram to show the different forces acting on a sailboat. 14 Module: Energy and Motion