The goal of this activity is to develop a model of the relationship between mass and speed for a system composed of an object acted upon by a constant amount of work. Students develop an understanding of the relationship between mass and speed for a given energy transfer into the system.

In the Preliminary Observations, students observe the speed of an object moving due to a repeatable amount of work. The mass will be changed by some significant factor and the resulting change in velocity observed.

During the subsequent inquiry activity, students may use a photogate, motion detector, Go Direct Sensor Cart, Motion Encoder, video analysis, or other tools to collect data for a low-friction cart on a level track or other similar system.

Students should complete the activity having evaluated data graphically and developed a mathematical model of the relationship between mass and velocity for a system for a given amount of work done on the system.


  • Design and perform an investigation.
  • Identify variables, design and perform an investigation, collect data, analyze data, draw conclusions, and formulate a model based on data from the investigation.
  • Create graphical representations of velocity of an object versus the mass of the object.
  • Create a mathematical model of velocity of an object with varying mass and a constant work input.