Galileo Lab Writeup

Garg 1 Rishi Garg Mr. McQueen Physics, 6th Period 26 October 2007 A Seventeenth-Century Galileo Experiment The following are graphs made from the data of the ball rolls, first with normal y-values, then with the y-values squared.

At first glance, I noticed that the average slopes of both graphs are negative. If one averaged all the values, and made one line for each graph, I believe that the line would be fairly straight. I first thought that meant that the average acceleration was also a constant value. However, after calculating and graphing the average accelerations, I knew that I was wrong.

Disregarding the last value, as it did not match the pattern and is therefore an outlier, the line looks as if it has a less negative slope as it progresses. This means that the average acceleration of the ball was in fact not constant at all, therefore disproving Galileo’s definition of acceleration. Scientifically, this makes sense. The ball’s acceleration was equal to the force of gravity, which is approximately -9.81 m/s2. Since acceleration is measured in units per units per units, gravity pulled the ball down at an initial velocity, then added a certain velocity to the initial velocity for every second that had passed while the ball was rolling. The graph of position vs.

Garg 2 time had a constant slope because each time the ball was rolled from 35 cm higher than the previous roll, a certain velocity was added to the previous velocity due to gravitational pull.

Garg 3

Garg 4

I didn’t see any surprises in my data. I did notice, however, a lot of data which didn’t seem to fit the general pattern of the rest of the data. I credited these anomalies to the fact that the timing and release of the ball was not exactly the same every time. Sometimes we used a ruler to release the ball; sometimes we simply used a finger. If we were to do this experiment again, we would use the ruler to release the ball in every trial. Also, when we were timing the roll with the water clock, we switched the person who operated the clock halfway into the experiment. Since different people operate the water clock in different ways, this odd incident probably altered our timings. Next time, we would have the same person operate the water clock for the entirety of the experiment.