Roth+Lab+2+Graph+Matching

Graph Matching **Position-Time Graph:** When the slope of a position-time graph is positive, the object in motion is experiencing a positive velocity (meaning that the object is moving forward at a specific speed that is determined by the slope), which in this lab is measured in meters per second (m/s). When the slope of a position-time graph is negative, the object in motion is experiencing a negative velocity, meaning that the object is moving backwards at the speed determined by the slope. When the slope is zero, the object is not moving in either direction. When a position-time graph crosses the x-axis, the position at that time is zero units of length (In this lab it would be 0 meters). In the lab, this never occurred because the person being studied always started walking 1 meter away from the motion detector. If the person were standing zero meters away from the motion detector, then the person would be right up against the motion detector which could move the motion detector and alter the measurements.

**Velocity-Time Graph:** When the slope of a velocity-time graph is positive, the object in motion is experiencing positive acceleration, meaning that the object whose motion is being measured is increasing its speed in a forward direction. Acceleration is measured in meters per second per second (m/(s^2)). When the slope of a velocity-time graph is negative, the object in motion is experiencing negative acceleration, which is an increase in speed in the backwards direction. When the slope is zero, there is no acceleration and the velocity remains constant for that period of time. When the line crosses the x-axis, the velocity is zero, meaning that the object is not moving. This occurred in the lab because there were times when the object being studied stopped.