Motion in Our Lives

• uniform motion


  movement at a constant speed and in a straight line
• nonuniform motion


  movement that involves changes in speed and/or distance
• scalar quantity


  a quantity that has a magnitude, but no direction. E.g. a distance of 2.2 m, a time of 6.0 s, speed of 102 km/h
• vectors


  have both magnitude and direction. E.g. a displacement of 2.2 m [N], a velocity of 100 km/h [N 15 E], a force of 7.65 N [40 E of N]
• average speed


  defined as total distance divided by time.

  average speed is different from instantaneous speed (speed at a particular instant)