Friction worksheet-1_317936119.docx lab friction

docx

School

Louisiana State University *

*We aren’t endorsed by this school

Course

MISC

Subject

Mechanical Engineering

Date

Dec 6, 2023

Type

docx

Pages

3

Uploaded by Lories504

Report
Name: Lories Thompson Phys112 - _____ Static and kinetic friction PART I. 1. Insert the force vs. time graph. Label the portion of the graph corresponding to the block at rest, the time when the block just started to move, and the time when the block was moving at constant speed. 2. Compare the force necessary to keep the block sliding compared to the force necessary to start the slide. 3. The coefficient of friction is a constant that relates the normal force between two objects (blocks and table) and the force of friction. Based on your graph, would you expect the coefficient of static friction to be greater than, less than, or the same as the coefficient of kinetic friction? PART II. 4. Record the data Peak static friction Average Total mass (m) Normal force (N) Trial 1 Trial 2 Trial 3 peak static friction (N) 0.133kg 1.3 N 0.7981 0.8860 0.4430 0.7090 0.383kg 3.75 N 1.951 1.626 1.596 1.7243 0.633kg 6.20 N 4.525 4.821 5.294 4.880 0.883 kg 8.65 N 4.909 4.909 5.826 5.215 1.133 kg 11.10 N 6.744 5.738 8.430 6.971 Kinetic friction Average Total mass (m) Normal force (N) Trial 1 Trial 2 Trial 3 kinetic friction (N) 0.133kg 1.3N 0.3284 0.3073 0.2985 0.3114 0.383kg 3.75N 0.8297 0.9334 0.9160 0.8930 0.633kg 6.20N 1.574 1.469 1.735 1.593 0.883kg 8.65N 2.651 2.277 2.188 2.372 1.133kg 11.10N 3.769 3.105 0.356 3.310 5. Calculate the normal force of the table on the block alone and with each combination of added masses (for a different total mass).
6. Plot a graph of the maximum static friction force ( y axis) vs . the normal force ( x axis). 7. Since F maximum static = μ s N , the slope of this graph is the coefficient of static friction μ s . Find the numeric value of the slope, including any units. Should a line fitted to these data pass through the origin? 8. In a similar graphical manner, find the coefficient of kinetic friction μ k . Use a plot of the average kinetic friction forces vs. the normal force. Recall that F kinetic = μ k N . Should a line fitted to these data pass through the origin? PART III. 9. Record the data Data: Block with no additional mass Trial Acceleration (m/s 2 ) Kinetic friction force (N) μ k 1 1.28 m/s 0.1702 0.1306 2 3 4 5 Average coefficient of kinetic friction: Data: Block with 500 g additional mass Trial Acceleration (m/s 2 ) Kinetic friction force (N) μ k 1 2 3 4 5 Average coefficient of kinetic friction: 10. These data also allow you to determine μ k . Draw a free-body diagram for the sliding block. The kinetic friction force can be determined from Newton’s second law, or Σ F = ma . From the mass and acceleration, find the friction force for each trial, and enter it in the data table. 11. From the friction force, determine the coefficient of kinetic friction for each trial and enter the values in the data table. Also, calculate an average value for the coefficient of kinetic friction for the block and for the block with added mass. 12. Does the coefficient of kinetic friction depend on speed? Explain, using your experimental data. 13. Does the force of kinetic friction depend on the weight of the block? Explain. 14. Does the coefficient of kinetic friction depend on the weight of the block?
15. Compare your coefficients of kinetic friction determined in Part III to that determined in Part II. Discuss the values. Do you expect them to be the same or different?
Your preview ends here
Eager to read complete document? Join bartleby learn and gain access to the full version
  • Access to all documents
  • Unlimited textbook solutions
  • 24/7 expert homework help