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

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

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

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.

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

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