Report

Describing Motion with Diagrams Describing Motion with Diagrams • Ticker Tape Diagrams Ticker Tape Diagrams The distance between dots represents the object’s change in position during that time interval Ticker Tape Diagram A changing distance between dots indicates a changing velocity – acceleration Graphing Motion Graphing Motion ZERO MOTION The object is at rest Position-time graph (x vs t) position of an object remains constant over time Velocity-time graph (v vs t) object is not moving, it has 0 velocity Acceleration-time graph (a vs t) If the object’s velocity is not changing, its acceleration is 0 Sketch above graphs Graphing Motion Uniform Motion – Constant Velocity x vs t graph as time increases so does the position *slope of a x vs t graph = velocity v vs t graph velocity remains constant over time *this should reflect the value of the slope of the x vs t graph a vs t graph velocity is not changing, acceleration is 0 *slope of a v vs t graph is acceleration Graphing Motion Uniform Accelerated Motion x vs t graph – position is increasing exponentially with time (acceleration) v vs t graph – velocity is increasing with time (acceleration) a vs t graph – acceleration is constant. • The value of a is equal to the slope of the v vs t graph • Acceleration will always be a horizontal line Position time graph Tangent Lines x t On a position vs. time graph: SLOPE VELOCITY SLOPE SPEED Positive Positive Steep Fast Negative Negative Gentle Slow Zero Zero Flat Zero Position time graph x Increasing & Decreasing t Increasing Decreasing On a position vs. time graph: Increasing means moving forward (positive direction). Decreasing means moving backwards (negative direction). Position time graph x Concavity t On a position vs. time graph: Concave up means positive acceleration. Concave down means negative acceleration. Describe the motion • This object is moving in the positive direction and accelerating in the positive direction (speeding up). • This object is moving in the negative direction and accelerating in the negative direction (speeding up). • This object is moving in the negative direction and accelerating in the positive direction (slowing down). Try this Area under a v vs t graph The area of a v vs t graph is displacement