Galileo Lab

What’s the best way to test whether Galileo was really as brilliant with gravity as we think he was? Test out his theories first hand of course! By measuring whether or not the distance a ball rolls down an inclined plane is really proportional to the time it takes squared, we can revisit one of Galileo’s theories.

The Backround          

Galileo Galilei was an Italian mathmetician, astronomer, and a premier physicist. He was the first man to see sunspots and proved that Venus orbited the sun. He also showed society that any object no matter what it’s weight would fall at the same rate because of gravity. This means that any two objects dropped at the same height will hit the ground at the exact same time. To understand uniform velocity and acceleration, Galileo measured the movement of balls down inclined planes. This would slow down the vertical component of the balls motion because the vertical movement is a constant accelerated motion. This led Galileo to discover that the distance a falling object travels is proportional to the square of the amount of time it takes for it to fall.

The Experiment

In order to test Galileo’s theory about the proportionality of falling objects to their time squared we needed to gather four main materials.

. A Stopwatch ( which I conveniently had on my wrist)

. Some sort of inclined plane, in our case we used medal ramps.

. A meterstick to measure the distance traveled.

. A metal ball.

Procedure-

First go to a flat surface such as a table with all your materials.   Set up at least 5 different heights with the inclined plan to roll the ball down and hit the table. With each different set of heights, measure the horizontal distance the ball will roll. After doing this, drop the ball from each different height and measure the amount of time it takes for the ball to hit the table using the stopwatch. Record all the data on some sort of spreadsheet, then graph the data. If there is an obvious line that can be drawn through the data, then you have proved Galileo’s proportional theory to be correct.

Time (sec)			Distance (cm)	Time2
0.5			20	0.25
0.6			30	0.36
0.8			40	0.64
1			50	1
1.2			60	1.44

 

After viewing our data our group came to the conclusion that the distance a falling object travels is proportional to the square of its time.  A trend line could be drawn between the data points, and the scatter plot is not sporadic at all. As for improvements to the experiment, rather than a TIMEX stopwatch, a motion sensor could have been used to more accurately measure the time it took for the balls to roll down the inclines. Overall though, the data taken was close enough with the instruments that we had at hand, and had enough evidence to prove Galileo’s theory on gravity correct.