Position or Velocity?

    Position or Velocity?

     Part of the science of physics is the measurement of the motion of objects. This includes plotting an object's position, velocity, acceleration and other relevant data. The graphical representation of one form of motion can lead to the graphs of the other forms of motion. The various graphical representations of motion are related through the slopes of each graph.

     It is important to note the differences of velocity, position, and speed.  It is also important to note that each graph can relate to other graphs.  For example, a position and time graph can relate to a velocity and time graph.
     The position-time graph is used to describe the motion of an object over a period of time. The slope of the position-time graph reveals important information about the velocity of the object. The slope of a position-time graph reveals the type of velocity an object undergoes during its motion. If the slope of a position-time graph is constant, this indicates a velocity that is constant. A position-time graph with a varying slope indicates a changing velocity. This relates directly to the motion lab because that was the idea of the lab: to show how velocity and position are related, but are different.  
     The velocity-time graph of an object reveals the speed at which an object is moving at a given time and whether it is slowing down or speeding up.  The slope of the velocity-time graph reveals the acceleration of an object. If the slope of the velocity-time graph is a horizontal line, then the acceleration is 0. This means the object is either at rest or moving at a constant speed, without speeding up or slowing down. If the slope is positive, then the acceleration is increasing. If slope is negative, acceleration is decreasing. (on a motion map, a resting movement is written as multiple dots at the same position)
     It is also crucial to know speed is a scalar quantity and velocity is a vector quantity.  The difference of the 2 are dependent on one variable: direction.  Speed measures the magnitude of the quantity.  Velocity measures the magnitude, but also factors in direction.  


Well that blog was a lot of information in little time!  Here is a small review:

1. Velocity-time graph and a position-time graph relate to each other, but are not the same.
2. Velocity considers the motion and direction of an object.
3. Speed considers the motion.

Website Links:

http://www.ehow.com/info_8472236_difference-graph-position-time-graph.html#ixzz2k1urev00

http://www.physicsclassroom.com/Class/1DKin/U1L1d.cfm

http://www.physicsclassroom.com/Class/1DKin/U1L3a.cfm