Hanging Bridge Lab

 Hanging Bridge Lab

Post Lab Write Up:

1. The graphs should match early on when the weight of the masses is less, but as you increase the masses the graphs start to diverge.
2. The limitations that my group observed were the lack of precise tools. For example taking measurements with a meter stick and "eyeballing" measurements. Our system is also not ideal, meaning that things like the string, the pulley, and how we arrange the masses must be taken into account.
3. The vertical displacement increases as the mass of the center object increases. However, the model created is really only useful for smaller masses (because the curves diverge the more mass you add).
4. My groups predictions somewhat agreed with the results of the lab. As you add more mass to object B the displacement becomes larger. The predicted equation for the model assumes ideal string and pulley, which we know not to be true.
5. No, the pulley doesn't behave in a frictionless way throughout the experiment. The less mass there is the closer the curves match, which means the pulley can be neglected (considered frictionless). However, this does not hold true as you begin to add more mass to object B. Therefore, the pulley can't always be considered frictionless. We also know that string itself is light and shouldn't interfere with experiment. As explained in class, a heavy string is more unpredictable compared to a light string.
6. The information needed would be: length of the walkway, mass of the walkway, mass of object on the walkway, density of rope (cable), effective mass of the pulleys, hanging mass on either side of the walkways.