MOVEMENT OF OBJECTS - LAB

OBJECTIVE:
Identify the difference between speed, velocity, and acceleration.

BACKGROUND:
Speed is a basic property that relates distance to time.  An automobile for example, travels a so many miles per hour at any given speed (or velocity).  Speed is simply the ratio of distance traveled per time:    

            speed = distance/time

If there is no variation, we can refer to this motion as constant speed, where equal distances are covered in equal intervals of time.  The speed at one instance is called instantaneous speed and is read by the speedometer.

When we describe speed and the direction of motion we are specifying velocity.  If we say that a body moves at a rate of 40 miles per hour to the north, this is velocity.  Constant velocity implies constant speed and direction.  A car in a circular track may have a constant speed but the velocity is changing. 

Any change of speed or velocity is called acceleration,  In a car, acceleration would be called pick-up.  It is the time rate of change, which refers to a decrease and increase of speed.