Motion Learning Objective: Students will learn how to describe motion using the terms distance, displacement, speed, velocity, and acceleration. The will learn how to interpret graphs of motion.

How Can you describe an objects motion? You are in a stationary car and another car passes you. How would you describe the motion of the other car?

Are you Moving? If you are sitting in a chair, and your chest is moving up and down, are you in motion?

Motion An object is in motion if its distance from another object is changing To decide if you are moving, you use a reference point. A reference point is a place or object used for comparison to determine if something is in motion. When you are sitting in a chair , your chair becomes your reference point. An object is in motion if it changes position relative to a reference point.

When you have selected your reference point use + or – signs to stand for opposing positions Left Right up D own You can also use + and – for away from or toward, in front of or behind.

Discussion Question Question A- Are the passengers in a boat moving compared to a person standing on the shore? Why or why not? Question B= Are seated passengers in a boat moving compared to the boat? Why or why not?

Answers Question A- Yes. The distance between the passenger and the person on the shore is changing. Question B- No. The distance between the boat and the passengers does not change.

Relative Motion In order to determine if you are moving or not you must look at your reference point. If your reference point is the chair and you are watching someone read, you would say they are not moving. You and your reference point are moving with the earth. If your reference point is the sun, then you are moving quite rapidly (30 kilometers every second!)

Distance and Displacement Distance: is the length of a path between two points Displacement: is the length and direction that an object has moved from its starting point Distance is the total length of the actual path between two points. Displacement is the length and direction of a straight line between starting and ending points.

Distance: 3 blocks from My house to the Police station. Displacement: The blue line shows displacement between two points

Vector Vector: A quantity that consists of both a magnitude and a direction. Displacement is a vector, but distance is not. Examples of vectors: acceleration, force, velocity. Vectors are shown graphically by using an arrow. The length of the arrow represents the vector’s magnitude. The direction of the arrow indicates the direction of the vector.

Key Vocabulary Motion- The state in which one objects distance from another is changing Reference point- a place or object used for comparison to describe the position or motion of a person or object Distance-the length of a path between two point Displacement- the length and direction of a straight line between starting and ending points Vector- a measurable quantity that consists of both a magnitude and a direction