8 September 2014 Modeling Air Resistance

Purpose: Part 1: To determine the relationship between air resistance force and speed.
                Part 2: Model the fall of an object including air resistance.

Equipment used:
     1. 15 Coffee filters of the same size: to drop and measure air resistance
     2. A 2 meter stick
     3. A Macbook Pro with Logger Pro, Video Capture, and Microsoft Excel: To map and chart the
     data

     The two pictures below show two of five separate tests where we as a class, in our groups, in

dropped five sets of coffee filters from a balcony. The the sets consisted of 1, 2, 3, 4, and 5 coffee

filters respectively. Using video capture on the Macbook Pro we were able to record the fall of the

coffee filter(s). With Logger Pro we were able to map out the rate and acceleration at which the

coffee filter(s) fell. The dots represents the approximate location of the coffee filter(s) at some time.

The 2 meter stick was used to scale our distance during the fall of the coffee filter(s).

Pictures of Video Capture Analysis

     Below are the five position over time graphs that we found and their respective slopes.

     Above is our mg vs velocity graph as the set of 5 coffee filters worked best we shall use this below 

to compare our experimental data against our theoretical data. The slope becomes our k that is 

     While we were gathering our equipment for the lab we found that the coffee filters that we used 

were each roughly gram making mg=0.01 N. Using the slopes of ends of the position over time 

graphs we had the terminal velocity. 

   

  The sum of all forces for this lab was ∑F=ma=mg-R this give us an acceleration of a=(mg-R)/m. 

R is the force of air resistance. Using the model R=k*v^n where k is some constant and n is some 

power we were able to insert it into our formula for acceleration a=g-k(v^n)/m. When the

acceleration is 0 k becomes 0=9.8-k((2.771)/0.005) k comes