Chapter 2Representing Motion

2.1- Picturing Motion I can diagram motion by using motion

diagrams, particle models, and coordinate systems

How can you tell something has moved?

What does this mean: Motion is relative.

Motion Diagrams vs. Particle Model Series of images

showing the positions of a moving object at equal time intervals

Simplified version of a motion diagram in which the object in motion is replaced by a series of single points

1. Draw a motion diagram of a runner

Label the time in each picture

3. What are the two components used to define motion?

2. Draw a particle model of a bird flying

4. Give three examples of straight-line motion.

2.2- Where and When? I can determine what measurements

are vectors and which are scalars.

Coordinate System- tells you the location of the zero point of the variable you are studying and the direction in which the values of the variable increase

Origin- the point at which both variables have the value zero

Position- the separation between an object and the origin

Distance- how far the object is from the origin

Vectors Scalars Have both

magnitude and direction› Examples:› 10 books to the left› 25 students back› 12 km/h west

Only has magnitude› Examples: › 10 books› 25 students› 12 km/h

A student travels south 20.0 meters and east 14.0 meters. What is the distance from his origin to final location “as the crow flies”?

Use skills learned in Algebra!

Math Practice:

Time Interval- difference between two times› Δt= tf-ti

› Final Time minus Initial Time Displacement- Difference between

origin and final location› Δ d= df-di

› Final Position minus Initial Position

2.3- Position Time Graphs I can find the change in time and

displacement and plot it on a position-time graph to determine velocity.

2.4- How Fast? I can use equations to solve for

average and instantaneous velocity.

Average Velocity› v=Δd/Δt› Average velocity is defined as the change

in position, divided by the time during which the change occurred.

› Velocity vs Speed

Instantaneous Velocity- the speed and direction of an object at a particular instant

One Sentence Summary Read pages 46-47 Average Velocity on

Motion Diagrams. Write a one sentence summary as an

exit slip for today!