September 12th, 2016: LAB 4: Object in Free Fall with Force of Air Resistance

Michell Kuang
Lab partners: Charles, Anthony
Date performed: 09/12/16

PART 1:
In the first part of this lab, we experimented with an actual falling object, using logger pro and video capture to help us get our data. We do this to determine the relationship between the air resistance force and speed.

Using the video capture feature in logger pro, we recorded 6 runs of a falling object (we used coffee filters). The first run had 1 coffee filter, the second had 2, and so on. There is a feature on logger pro that allows us to track the movement of the coffee filter on video by marking its position frame by frame. We set the 1 meter mark, and then did this with every run. Then, with our recorded data, we again used logger pro, this time utilizing its graph and equation fit functions, and applying a linear fit for the position vs. time graph. 

Logger Pro view: Run with 1 coffee filter; data of time and position and graph with linear fit

The slopes given in the statistics boxes of our graphs from each run are our estimated terminal velocities. We took these values of each run and plotted them onto a new logger pro file. Then, we formatted it so that our variables fit appropriately with the function we want, and we got our values of k and n from the fit for the graph. The uncertainties are also given.

Logger Pro view: Plotted data with graph; Value of A is k and value of B is n

PART 2:

In the second part of the lab, we charted our data on the lab following the model of a power law: 

Fresistance = kv^n

Following this model, we are able to predict the terminal velocity of each run. Along with some constants, we had columns for various variables including time, velocity, position, and more.

Excel sheet of plotted data to find terminal velocities

A lot of the data on my lab is not consistent with the data shown in certain pictures because we messed up and didn't correctly label our videos. To produce data with runs of varying number of coffee filters, we used some of another group's videos. The data consequently became inconsistent and incorrect.