Hanging Bridge Lab

Where do the two curves match?  Where do the two curves start to diverge from one another?  What does this tell you about the system? 

- The curves match at the point (0.126,11.36) . So in theory based off the measurements taken in class and the equation we derived the two measurements would be the same if we added 0.126kg to the bridge which give us a displacement of 11.36cm.  

- The two curves diverge from each other drastically once we start to add 0.2kg at 0.5kg intervals. 

What are the limitations on the accuracy of your measurements and analysis?

- The limitations on the accuracy of our measurements are highly dependent on human error, assuming the system was at perfect equilibrium, determining the displacement of the weights.

What will you report to your supervisor?  How does the vertical displacement of an object suspended on a string between two pulleys depend on the mass of that object?

- As the mass of M increases, the tension in the string must increase to support it. But because the side masses m are fixed, the only way to balance the increased downward force from M's weight is to increase the vertical component of the tension in the string.

Did your measurements of the vertical displacement of object B agree with your initial predictions?  If not, why?  State your result in the most general terms supported by your analysis. 

- no our measurements of object B did not agree with our initial predictions because there may have been a mistake in taking the measurements or performing the calculations during the analysis. Also the analysis is derived from a perfect system excluding outside limiting factors that may have caused us to have incorrect measurements. 

Do the pulleys behave in a frictionless way for the entire range of weights you will use?  How can you determine if the assumption of frictionless pulleys is a good one?

- Pulleys will most likely not behave in a frictionless way for the entire range of the weights that we will use because at very low weights the tension in the rope will not be enough to overcome pulley friction and at very high weights friction may be noticeable if the the pulley bearings or axles have limits or wear on them. 

- We can determine if the assumption of a frictionless pulley is a good one by performing a symmetry test or add mass at small increments. 

What information would you need to apply your calculation to the walkway through the rain forest?

- Information we would need to apply our calculations to the walkway in the rain forest would be:

    - mass of the person or load 

    - tension strength of the rope

    - length and height of the cable

    - distance from the person to anchor

    - material of the rope

    - friction at the pulleys