Unit 11 Lesson 1 What Is Motion? Copyright © Houghton Mifflin Harcourt Publishing Company 1

How can you tell something is moving? Unit 11 Lesson 1 What Is Motion? How can you tell something is moving? Copyright © Houghton Mifflin Harcourt Publishing Company 2

Unit 11 Lesson 1 What Is Motion? Twisting and Turning Position is the location of an object in relation to a nearby object or place. The second object or place is called a reference point. An object that moves has motion. Motion is a change in position. Copyright © Houghton Mifflin Harcourt Publishing Company 3

Twisting and Turning Unit 11 Lesson 1 What Is Motion? 4 Copyright © Houghton Mifflin Harcourt Publishing Company 4

Twisting and Turning Unit 11 Lesson 1 What Is Motion? 5 Copyright © Houghton Mifflin Harcourt Publishing Company 5

Where Is It? Unit 11 Lesson 1 What Is Motion? 6 Copyright © Houghton Mifflin Harcourt Publishing Company 6

Unit 11 Lesson 1 What Is Motion? Fast or Slow? Speed tells you how the position of an object changes during a certain amount of time. An example of speed is 2 meters traveled every second, or 2 m/sec. To find an object’s speed, divide the distance the object travels by the time it took to travel that distance. Copyright © Houghton Mifflin Harcourt Publishing Company 7

Fast or Slow? Unit 11 Lesson 1 What Is Motion? 8 Copyright © Houghton Mifflin Harcourt Publishing Company 8

Unit 11 Lesson 1 What Is Motion? Fast or Slow? Velocity is the speed of an object in a particular direction. An example of velocity is 2 m/sec, east. Copyright © Houghton Mifflin Harcourt Publishing Company 9

Fast or Slow? Unit 11 Lesson 1 What Is Motion? 10 Copyright © Houghton Mifflin Harcourt Publishing Company 10

Unit 11 Lesson 1 What Is Motion? Pushes and Pulls A push or pull is a force. A force can change an object’s speed or direction. Gravity is a force that pulls objects down to Earth. Friction is a force that acts directly against the direction of motion. Friction can slow things down or make them stop. Copyright © Houghton Mifflin Harcourt Publishing Company 11

Pushes and Pulls Unit 11 Lesson 1 What Is Motion? 12 Copyright © Houghton Mifflin Harcourt Publishing Company 12

Pushes and Pulls Unit 11 Lesson 1 What Is Motion? 13 Copyright © Houghton Mifflin Harcourt Publishing Company 13

Changing It Up Acceleration is any change in velocity. Unit 11 Lesson 1 What Is Motion? Changing It Up Acceleration is any change in velocity. An object accelerates if it speeds up, slows down, or changes direction. If a force pushing against an object in one direction is greater than a force pushing in the opposite direction, the object will accelerate. Copyright © Houghton Mifflin Harcourt Publishing Company 14

Changing It Up Unit 11 Lesson 1 What Is Motion? 15 Copyright © Houghton Mifflin Harcourt Publishing Company 15

Changing It Up Unit 11 Lesson 1 What Is Motion? 16 Copyright © Houghton Mifflin Harcourt Publishing Company 16

Unit 11 Lesson 1 What Is Motion? Copyright © Houghton Mifflin Harcourt Publishing Company 17