Lab 3/20: Vertical Displacement Bridge

Lab 3/20: Vertical Displacement Bridge

Vertical Displacement was measured at different points by changing the mass in the center and keeping the masses on the edges the same. Using the equation, length of string*(TAN(ASIN(force of object/(2*force of weights))))*0.5, we plotted the calculated displacement alongside the experimental displacement on a graph. To find uncertainty, the displacement was measured using different masses whose sum was 200g and recorded the data in the table.

Results

Analysis

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 when the mass of the object is smaller, around 100-180 grams. Then around 180 onwards the calculated displacement increased at a faster rate than what was observed through experimentation. This tells that the experiment will be more accurate with smaller masses since the smaller systems corroborate the experimental and theoretical data.

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

We are only using measurements of length and mass so we are limited by the tools we use like the rulers and meter stick. Additionally, since we are using real-life equipment the pulleys and string are not ideal so they will affect the accuracy of our calculations

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?  

The vertical displacement increases as the mass of the object increases as the graph shows. However, as the mass increases, the experimental data weans off from the theoretical data so the model would be more accurate with smaller masses. It is predicted to be this way since as the tension increases from the weight of the mass, the pulley becomes less ideal as it

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. 

They generally agreed with the predictions but did not increase to the same order. We only accounted for ideal conditions which isn't realistic with experimental data. The smaller the mass, the more accurate the results. The higher the mass, the more tension occurs which causes the model to fail.

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

Information needed would be the mass of the bridge, the strength of the cable, and the friction from the pulleys.

Uncertainty Calculation on Sheets

* Used "STDEV(G2:G4)" for Standard Deviation and "=SQRT(((B7-C2)^2 +(B7-C3)^2 +(B7-C4)^2)/3)" for Uncertainty