Lots of objects go back and forth; that is, they move along a path first in one direction, then move back the other way. An oscillating pendulum or a ball tossed vertically into the air are examples of things that go back and forth. Graphs of the position vs. time and velocity vs. time for such objects share several features. When an object changes speed or direction, it accelerates. By examining the graphs, you will be able to tell if an object is accelerating. In this experiment, you will observe several objects that change speed and direction as they go back and forth:

  • Oscillating pendulum
  • Dynamics cart rolling up and down an incline
  • Student jumping into the air
  • Mass oscillating at the end of a spring
  • Ball tossed into the air

Analyzing and comparing graphs of the motion of these objects will help you to apply ideas of kinematics more clearly.


  • Qualitatively analyze the motion of objects that move back and forth.
  • Analyze and interpret back and forth motion in kinematics graphs.
  • Use kinematic graphs to catalog objects that exhibit similar motion.