Kinetic Friction Lab Purpose: To measure the coefficient of kinetic - - PowerPoint PPT Presentation

Kinetic Friction Lab

Purpose: To measure the coefficient of kinetic friction between several surfaces. Prelab Discussion:

• A spring scale is a device for measuring force.
• How can we find the coefficient of kinetic friction with a spring scale?
• What measurements will you need to take?
• How can we get the best measurement of the coefficient of kinetic

friction?

• What will you vary and how?

Kinetic Friction Lab

Notes on the Procedure

• The spring scale needs to be zeroed – use the small white nob on the

end of the scale.

• Be careful with the scales – don’t pull too hard or they will break.
• Take measurements for at least 5 different measurements (different

normal forces) for 3 different surfaces.

• Please use descriptive names for your three surfaces (NOT surface 1,

surface 2, etc.)

Kinetic Friction Lab - Analysis

• Be sure that your data tables include both your original measurements

and your calculated values. (e.g. weight from mass)

• You should have three graphs – one for each surface. What is the

shape of each graph?

• Be sure to properly label your graphs
• Don’t forget your units
• In your column headers
• On your graph axes
• On both the slope and y-intercept of your equations for the best-fit line

Kinetic Friction Lab - Discussion

• What is your mathematical model for the relationship between the

normal force and the force of kinetic friction?

• What is the coefficient of kinetic friction (mk) for each of the three

surfaces?

• Which surface has the highest mk? Which has the lowest? Does this

make sense?