1. A Picture is Worth 103 Words & Other Words of Wisdom
Motion Graphs
A Picture is Worth 103 Words
& Other Words of Wisdom

2. Outline A quick review of basics- Slopes and change
Motion Graphs and Derivatives W.S. 1-8
New ideas- Negative velocity
Acceleration Concepts
WebAssign Examples
Reading Guide
Homework:
9-16 on W.S.
WebAssign #5 Due date pushed back 2 days to Tuesday 9/22
Ch.2&3 Reading Guide

3. Toward is negative. Away is positive.
Position (distance - x) vs. time
Basics about position vs. time graphs:
Everything starts with location/position in physics.
We will use motion sensors (“electronic bats”) to measure this.
Displacement is Dx=xf-xi
Toward is negative. Away is positive.
Always relative to a “Frame of Reference” (0,0) Origin

4. Velocity= the rate of change of displacement. OR
Velocity= the rate of change of displacement OR Speed+ Direction (Vector)
The slope of a position vs. time graph (Nickname: “xt graph”) is velocity.
In this case, the average slope and instantaneous slopes are the same. (Constant Slope)
Always find velocity; speed is just the absolute value of the velocity.

5. When a position time graph is “curvy”, velocity changes.
Curves have “instantaneous slope” and “average slope”.

9. The area= Displacement, Dx the slope of a “vt” is acceleration.