Chapter Menu Chapter Introduction Lesson 1Lesson 1Describing Motion Lesson 2Lesson 2Position and Motion Lesson 3Lesson 3Acceleration Chapter Wrap-Up

Chapter Introduction What are some ways to describe motion?

Chapter Introduction What do you think? Before you begin, decide if you agree or disagree with each of these statements. As you view this presentation, see if you change your mind about any of the statements.

Chapter Introduction 1.Displacement is the distance an object moves along a path. 2.The description of an object’s position depends on the reference point. 3.Constant speed is the same thing as average speed. Do you agree or disagree?

Chapter Introduction 4.Velocity is another name for speed. 5.You can calculate acceleration by dividing the change in velocity by the change in distance. 6.An object accelerates when either its speed or its direction changes. Do you agree or disagree?

Lesson 1 Reading Guide - KC How does the description of an object’s position depend on a reference point? How can you describe the position of an object in two dimensions? What is the difference between distance and displacement? Position and Motion

Lesson 1 Reading Guide - Vocab reference point position motion displacement Position and Motion

Lesson 1-1 A description of a location usually states the location relative to a certain point. Describing Position relative Science Use compared (to) Common Use a member of your family

Lesson 1-1 A position is an object’s distance in a certain direction from a reference point.position A reference point is a starting point that can be used to locate a place or thing.reference point Describing Position

Lesson 1-1 A complete description of your position includes a distance, a reference direction, and a reference point. Describing Position (cont.)

Lesson 1-1 The reference direction is the positive (+) direction and the opposite direction is the negative (-) direction. Describing Position (cont.)

Lesson 1-1 Describing Position (cont.) How does the description of an object’s position depend on a reference point?

Lesson 1-2 Describing Position in Two Dimensions (cont.) How can you describe the position of an object in two dimensions?

Lesson 1-3 MotionMotion is the process of changing position. Describing Changes in Position motion from Latin motere, means “to move”

Lesson 1-3 The man in the boat is not in motion compared to his fishing pole. He is in motion compared to the buoy.

Lesson 1-3 Displacement is the difference between the initial (first) position and the final position of an object.Displacement –Distance depends on the path taken. –Displacement depends only on the initial and final positions. Describing Changes in Position (cont.)

Lesson 1-3

Distance and displacement are equal only if the motion is in one direction. Describing Changes in Position (cont.) What is the difference between distance and displacement?

Lesson 1 - VS A reference point, a reference direction, and distance are needed to describe the position of an object.

Lesson 1 - VS An object is in motion if its position changes relative to a reference point.

Lesson 1 - VS The distance an object moves and the object’s displacement are not always the same.

Lesson 1 - Now 1.Displacement is the distance an object moves along a path. 2.The description of an object’s position depends on the reference point. Do you agree or disagree?

Lesson 2 Reading Guide - KC What is speed? How can you use a distance-time graph to calculate average speed? What are ways velocity can change? Speed and Velocity

Lesson 2 Reading Guide - Vocab speed constant speed instantaneous speed average speed velocity Speed and Velocity

Lesson 2-1 SpeedSpeed is a measure of the distance an object travels in a unit of time. What is speed?

Lesson 2-1 You can calculate speed by dividing the distance traveled by the time it takes to go that distance. What is speed? (cont.)

Lesson 2-1 Constant speedConstant speed is the rate of change of position in which the same distance is traveled each second. What is speed? (cont.)

Lesson 2-1 Instantaneous speed is speed at a specific instant in time.Instantaneous speed Average speed is the total distance traveled divided by the total time taken to travel that distance.Average speed What is speed? (cont.)

Lesson 2-2 Graphs that show comparisons between distance and time are called distance-time graphs. Constant speed is shown as a straight line on a distance- time graph. Distance-Time Graphs

Lesson 2-2 Distance-Time Graphs (cont.) If the speed of an object changes instead of being constant, its motion on a distance-time graph is a curved line.

Lesson 2-2 You can use distance-time graphs to compare the motion of two different objects. The steeper line indicates a faster speed. Distance-Time Graphs (cont.)

Lesson 2-2 You can use distance-time graphs to calculate the average speed of an object.

Lesson 2-2 Distance-Time Graphs (cont.) How can you use a distance- time graph to calculate average speed?

Lesson 2-2 Distance-Time Graphs (cont.) n-vs-time-graph-part-1 n-vs-time-graph-part-2

Lesson 2-3 VelocityVelocity is the speed and the direction of a moving object. Velocity velocity from Latin velocitas, means “swiftness, speed”

Lesson 2-3 The velocity of an object can be represented by an arrow. A greater speed is shown by a longer arrow. The arrow points in the direction of the object’s movement. Velocity (cont.)

Lesson 2-3 Velocity (cont.) Velocity changes when the speed of an object changes, when the direction that the object moves changes, or when both the speed and the direction change.

Lesson 2-3 Velocity (cont.) How can velocity change?

Lesson 2 - VS Speed is a measure of the distance an object travels in a unit of time. You can describe an object’s constant speed, instantaneous speed, or average speed. A distance-time graph shows the speed of an object.

Lesson 2 - VS Velocity includes both the speed and the direction of motion.

Lesson 2 - Now 3.Constant speed is the same thing as average speed. 4.Velocity is another name for speed. Do you agree or disagree?

Lesson 3 Reading Guide - KC What are three ways an object can accelerate? What does a speed-time graph indicate about an object’s motion? Acceleration

Lesson 3 Reading Guide - Vocab acceleration Acceleration

Lesson 3-1 Acceleration is a measure of how much the velocity of an object changes in a unit of time.Acceleration An object accelerates when its velocity changes as a result of increasing speed, decreasing speed, or a change in direction. Acceleration—Changes in Velocity

Lesson 3-1 Acceleration has a direction and can be represented by an arrow. Acceleration—Changes in Velocity (cont.)

Lesson 3-1 Acceleration—Changes in Velocity (cont.) What are three ways an object can accelerate?

Lesson 3-2 Acceleration is a change in velocity during a time interval divided by the time interval during which the velocity changes. Calculating Acceleration

Lesson 3-2 Acceleration is in the direction of motion if it is positive and opposite the direction of motion if it is negative. Calculating Acceleration (cont.)

Lesson 3-3 A speed-time graph shows how speed changes over time. A speed-time graph has time on the horizontal axis—the x-axis, and speed on the vertical axis—the y axis. Speed-Time Graphs

Lesson 3-3 Speed-Time Graphs (cont.) horizontal from Greek horizein, means “limit, divide, separate” vertical from Latin verticalis, means “overhead”

Lesson 3-3 An object at rest is not moving, so its speed is always zero. Speed-Time Graphs (cont.)

Lesson 3-3 For an object moving at constant speed, the speed-time graph is a horizontal line. Speed-Time Graphs (cont.)

Lesson 3-3 The line on the speed-time graph for an object that is speeding up has an upward slope. Speed-Time Graphs (cont.)

Lesson 3-3 Speed-Time Graphs (cont.) The line on the speed-time graph for an object that is slowing down has a downward slope.

Lesson 3-3 Speed-Time Graphs (cont.) What does a speed-time graph show about the motion of an object?

velocity-accelerationhttp:// velocity-acceleration vectorshttp:// vectors

Lesson 3-4 There are several ways to describe motion. You can describe position by direction and distance from a reference point. You can compare distance and displacement to find average speed. You can describe velocity by speed and direction. Summarizing Motion

Lesson 3 - VS An object accelerates if it speeds up, slows down, or changes direction.

Lesson 3 - VS Acceleration in a straight line can be calculated by dividing the change in speed by the change in time.

Lesson 3 - VS A speed-time graph shows how an object’s speed changes over time.

Lesson 3 - Now 5.You can calculate acceleration by dividing the change in velocity by the change in distance. 6.An object accelerates when either its speed or its direction changes. Do you agree or disagree?

Chapter Review Menu Key Concept Summary Interactive Concept Map Chapter Review Standardized Test Practice

The BIG Idea The motion of an object can be described by the object’s position, velocity, and acceleration.

Key Concepts 1 An object’s position is its distance in a certain direction from a reference point. The position of an object in two dimensions can be described by choosing a reference point and two reference directions, and then stating the distance along each reference direction. The distance an object moves is the actual length of its path. Its displacement is the difference its initial position and its final position. Lesson 1: Position and Motion

Key Concepts 3 Acceleration is a change in velocity over time. An object accelerates when it speeds up, slows down, or changes direction. A speed-time graph shows the relationship between speed and time and can be used to determine information about the acceleration of an object. Lesson 3: Acceleration