The purpose of this lab was to find out the angle the string makes as the rubber stopper spins, and also how long it takes for the stopper to make one rotation. This is done with an apparatus that the professor made with a motor that will spin a rubber stopper on a piece of string that is tied to a meter stick.
Experiment
Before we actually conduct the experiment we draw a diagram to figure out an equations for the angel that is going to be created, and how long it will take the rubber stopper to make one revolution.
Now we conduct the experiment with the apparatus, but before that we take measurements of the dimensions of the apparatus. After the measurements are taken we then conduct the experiment and spin the rubber stopper at six different speeds. At each speed we timed how long it would take for the rubber stopper to make ten revolutions, then divide by ten to fins how long it would take the rubber stopper to make one revolution. Along with the time it takes the rubber stopper to make one revolution, we also measure how far off the ground the rubber stopper was from the ground.
Once we have collected all the data we needed for all six trials we the take that data and plug it into the equations we found prior to the lab. The values that those equations give us are theoretical values of what the angle the string makes as it spins, and how long it takes for the rubber stopper to make one rotation.
To make any sense out of the data we collected and calculated we plot the theoretical data against our experimental data to see if they have a a slope of one. We want a slope of one because otherwise it would mean that in our theoretical calculations were off. This in turn would mean that we are off by a certain factor or that our whole equation was wrong.
For the graph we did a proportional fit and you can see that our slope is very close to one, and so we decided that even with the error that our model for calculating period was an accurate one. We decided that it was okay because the errors were very small and explainable. One source of error would be that there is a limit to how fast our reaction time is when we start and stop the timer for the each trial. Another would be that the meter sticks also have a margin of error, also uncontrollable factors such as the air drafts caused by vents.
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