Name: Lab Instructor Date Lab Experiment: A Seventeenth Century Experiment "Galileo's Inclined Plane" We will recreate Galileo's inclined plane experiment with some improvements. This experiment is similar to the one discussed by Galileo in the Two New Sciences. You will make quantitative measurements of the motion of a cart rolling down an incline. Galileo was interested in how the speed of objects in free fall (objects that only experience the force of gravity) increases in relation to time. He believed that the speed was directly proportional to the time, no matter the weight of the object. This was contrary to the accepted view of Aristotle that the rate of fall is directly proportional to the weight of the object and inversely proportional to the resisting force of the medium. (The heavier the object, the faster an object fell). Free fall was too rapid to measure, so Galileo assumed that the speed of a ball rolling down an incline increased in the same way as an object in free fall, only more slowly. Even a ball rolling down a shallow incline moves too fast to measure the speed for different parts of the descent accurately, so we will measure total time and total distance. We use this information to find average velocity, final velocity, and acceleration of the cart. To release the cart, hold it in place with a pencil or ruler and release it by quickly moving the ruler away from the cart down the inclined plane. Let's compare the experiment you will do to the one Galileo described in Discourses and Mathematical Demonstration Concerning Two New Science Pertaining to Mechanics and Local Motion (1638), 4 years before his death in 1642 (the year Isaac Newton was born). Galileo You wooden molding 12 cubits long with channel cut, lined with | metal track 1.2 m long parchment hard, smooth, very round bronze ball dynamics cart water clock (precision 1/10 pulse beat) stopwatch (1/10 second) 100 trials for each distance 4 trials for each distance Galileo's definition of uniform acceleration was "equal increases in speed in equal times." Galileo (and we) showed that if an object actually moved in this way, the total distance of travel should be directly proportional to the square of the total time of fall or d oct. Why was the equation d = 1/2 at more promising for Galileo than a = Av/At? How can you determine the angle of the track? What strategy would you use to determine the relationships among the variables? Use Excel to plot the following and determine the relationship between the two variables. Plot distance vs. time. Plot final velocity vs. time. Plot distance vs. time squared