Eugenia and David push on each other: Observational Experiment

Aim

To construct a relation/rule relating the force Eugenia exerts on David and the force David exerts on Eugenia when either one of them pushes the other.

Prior Knowledge

  • Kinematics: position, velocity and acceleration.
  • Graphing skills.
  • Newton's first law.
  • Newton's second law.
  • Reference frames.

Description of the Experiment

  • Carefully observe what happens when David pushes Eugenia and Eugenia pushes David.
  • Does it seem possible for David to push Eugenia without starting to move himself? Does it seem possible for Eugenia to push David without starting to move herself?
  • Addtional Information

    Eugenia's mass with gear: 52kg
    David's mass with gear: 83kg


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    Questions

For one particular trial when either David pushes or Eugenia pushes:

  • Decide what you need to measure to determine the speed of Eugenia and the speed of David after the push is over?
  • After the speeds have been determined, can you find the acceleration of David and the acceleration of Eugenia during the time interval when they are pushing each other?
  • What assumptions should you make in order to find their accelerations?
  • Use the information you have found and previously established relation between acceleration and force to compare the forces they exert on each other.
  • Repeat for the other trials
  • What can you conclude about the strength of the push of David on Eugenia as compared to Eugenia's push when Eugenia pushes David?
  • What can you conclude about the strength of the push of Eugenia on David as compared to David's push when David pushes Eugenia?