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?