Formal Lab_1(2014) - Jay Mathy Science Wiki

DSHS Physics Mathy
Lab #1
Do not write on this
Formal Lab #1 What a Drag
Drag Explained
Drag is the popular name for the force that is experienced by anything moving through a fluid. When an object has relative motion in a
fluid, drag is created. Most recently this force has been a hot topic of conversation at the 2008 summer Olympic games. Technology of
man made fibers have allowed swimsuits to reduce the drag encountered by the swimmers during their races and world records have
been broken in virtually every event. What was not discussed concerning these suits, however, was the relationship between the mass
of the swimmer and the drag produced. This shall be the premise for the problem explored in this lab. Since air is also a fluid ( a very
light one), we’ll use it instead of water. By dropping coffee filters onto a motion sensor, we will be able to discover a possible
relationship if one exists!
Quantify the relationship between mass and terminal velocity
Please generate a hypothesis at this point
5 Coffee filters
Pasco Software for Motion sensors
Digital Scale
IMac computer System 10.4
60 Hz motion sensor
1. Gather the materials you will need for this lab and turn on the Data Studio program on the computer. Make sure
the sensor bar is exactly in the middle of the ring stands vertical bar. This is the ideal height to drop the filter.
2. When DataStudio boots up, select the “Create Experiment” prompt / picture. You will click the “ Setup” icon
and choose the velocity box. You do not need the position function. Unselect it.
Drag the velocity “ person” icon down to the graph icon. A velocity – time graph will appear.
3. Measure the mass for each of the coffee filters and create a table to organize your data.
4. Now drop the coffee filter under the motion sensor as shown in the illustration. Do this from at least 10 cm the sensor.
Click the RUN button on the Data Studio screen and measure the filter’s terminal velocity (as an absolute value, negative
only indicates direction). This will be the maximum velocity the object reaches during its fall. This will be the last plot before
the graph jumps in the other direction . Record this velocity in your table. If your graph does not have a smooth arc, redo the
trial until you can accomplish one. It does take skill.
max velocity for last trial
5. Repeat step #4 for the next four filters. To increase the mass each time, place them inside each other each
time until you have dropped all five of them together at once.
6. You should have 5 separate runs on one graph . Screen capture this graph by using “ Command + option + 4”.
Put this graph on a Word document and shrink it so that 3-4 fit on a page. Put this graph in your lab book.
7. Using Microsoft Excel create a graph of terminal velocity vs mass. Pay attention to which is the dependent
variable and which is the independent variable. Remember, the independent variable goes on the x –axis.
8.Visually, the graph should show the trend line, a slope equation, and an R2 component!
These questions need to be answered before your conclusion!
1. What was the scientific problem that this lab sought to answer?
2. Restate the dependent and independent variables.
3. What is the relationship between the dependent and independent dependent variable (it is linear, parabolic….),
then describe it in mathematical terms (e.g. y= kx2 or y=k/x….etc)
4. What does your graph explain about your data?
5. What is the significance of your slope and your R2 value?
Write a conclusion based on the rubric you have been given for this class !