Teacher Edition

READING ENGAGE EXPLORE EXPLAIN ELABORATE EVALUATE Energy Transfer in Collisions 30 min pairs Inspect Read Tell students they are going to read this passage to learn about how energy is transferred. After reading, students will use what they have learned to answer a question about car collisions and the evidence they can site to explain how energy is transferred. Have students underline key words that tell what can happen to colliding objects. Encourage students to circle any confusing words or phrases. ASK: What does the word transform mean in this text? Sample answer: Energy changes from one form to another. In this text, energy changes from motion to sound and heat in Newton’s cradle. ASK: What is the main idea of the passage? Sample answer: Energy can be transferred in two types of collisions: elastic and inelastic. Lesson Vocabulary energy transfer Confirm students’ understanding of the content and explain that the common use of the word transfer means “to move.” Energy moves in an energy transfer. Find Evidence Reread Have the students reread the text using a Teacher Think Aloud. As you reread, emphasize text for students and answer questions about any text they circled. Ask for student volunteers to share the text they highlighted and continue with a class discussion of the similarities and differences in elastic and inelastic collisions. ASK: Why do the balls in Newton’s cradle eventually stop moving? Sample answer: Even though Newton’s cradle demonstrates an elastic collision where no kinetic energy is lost, the energy is transformed into sound and heat each time the balls collide, causing them to stop moving. Lesson 3: Energy Transfer in Collisions CLOSE READING Energy Transfer in Collisions Energy transfer is the movement of energy from one object to another. Newton’s cradle is a toy that shows how energy can be transferred. When you pull one ball up and release it, it will collide with the other balls. As a result of the collision, the ball on the opposite end swings out. Then that ball swings back and hits the other balls, causing the first ball to swing out. Energy is transferred from the first ball to the last and back again because of collisions. Newton’s cradle can be used to demonstrate an elastic collision . In elastic collisions, there is no loss of kinetic energy from the system. A system is a group of connected parts that make up a whole. The colliding balls in Newton’s cradle act as a system. If the collisions in Newton’s cradle were perfectly elastic, the balls would continue to bounce up and down forever. But even Newton’s cradle is not perfectly elastic. Over time, the balls decrease in height and will eventually stop. Some of the energy in Newton’s cradle transforms into sound and heat each time the balls collide. Energy is transformed when it changes from one form to another. Notes Inspect Read the passage Energy Transfer in Collisions . Underline text that explains how energy is transferred in a Newton's cradle. Find Evidence Reread the passage. Highlight text evidence that tells the differences between elastic and inelastic collisions. Newton’s cradle is a device that shows how energy is transferred in collisions. Copyright © McGraw-Hill Education Gyro Photography/amanaimagesRF/Getty Images 50 EXPLAIN Module: Energy and Motion 041_060_NA_SCI_SE_G4_MAL3U1_699632.indd 50 22/12/18 4:33 PM GO ONLINE INTERACTIVE PRESENTATION Close Reading: Momentum in Collisions 50 Module: Energy and Motion