Finding the coefficient of friction: Application Experiment

Aim

Determine the coefficient of kinetic friction between the tissue box and the table.

Prior Knowledge

• Constancy of momentum in an isolated system.
• Transformation of energy
• Kinetic energy, gravitational potential energy, internal energy, work
• Friction force, static friction force, kinetic friction force

Description of the Experiment

Observe the two experiments below. Use each to determine the coefficient of kinetic friction between the tissue box and the table. List all of the assumptions that you made. Describe how you will use the video to determine the necessary quantities. List all physics explanations/relations you will use to determine the coefficient of friction. Describe the mathematical procedure that you will use to find the coefficient of kinetic friction from the measured physical quantities. Decide whether you have a reasonable agreement between the results of the two experiments. Explain your decision.

Addtional Information

Carefully examine the assumptions that you use.

The flour-filled balloon has a mass of 54.7g, the tissue-box has a mass of 161.1g.

Youtube movies can be stepped frame by frame using the , and . keys on your keyboard. If you want to download the movie to your computer, right-click or control-click HERE.

Questions

1. What physics explanations/relations did you use to find the coefficient of friction?
2. Did the assumptions that you had made allow you to use these explanations/relations?
3. Describe the processes that occurred in the second experiment from the point of view of energy. What is the system/systems that you chose for your analyses?
4. Describe the processes that occurred in the second experiment from the point of view of momentum. What is the system/systems that you chose for your analyses?
5. Did the results from the two experiments match? If not, do you need to modify your assumptions or to to change the mathematical procedure or both?