The goal of this activity is for students to determine the relationship between work done on an object and the resulting change in kinetic energy.

In the Preliminary Observations, students observe the speed of an object that has had work performed on it. A cart on a track pushed by hand can be an effective initial observation, as well as the use of a human dynamics cart. For the next phase of the Preliminary Observations, modify the amount of work being done on the object, and observe the change how it moves. We recommend that this be done as a whole-class activity.

During the subsequent inquiry process, students may use a motion detector, a Motion Encoder, or a Go Direct Sensor Cart to collect data for a cart on a level track. There are a variety of methods for varying the work input and measuring the kinetic energy of the cart system.

Students should finish the activity having evaluated data graphically and developed a model of the relationship between work and change in kinetic energy.


  • Design and perform an investigation.
  • Draw a conclusion from evidence.
  • Identify that the work done on a system is equal to the change in kinetic energy.