Content

https://drive.google.com/drive/folders/1BvgWGdHko_8vQyHmhYY-_DA5bhmIGLte

Please create a lab report. Create a script I can use for a video presentation as well.

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An object that is falling through the atmosphere is subjected to two external forces. The first force is the gravitational force, expressed as the weight of the object, and the second force is the aerodynamic drag of the object. The weight equation defines the weight W to be equal to the mass m of the object times the gravitational acceleration g: W = m * g the value of g is 9.8 meters per square second on the surface of the earth. The gravitational acceleration decreases with the square of the distance from the center of the earth. But for most practical problems in the atmosphere, we can assume this factor is constant. If the object were falling in a vacuum, this would be the only force acting on the object. But in the atmosphere, the motion of a falling object is opposed by the aerodynamic drag. The drag equation tells us that drag D (or R) is equal to a drag coefficient Cd times one half the air density r times the velocity V squared times a reference area A on which the drag coefficient is based: On the figure at the top, the density is expressed by the Greek symbol “rho”. The symbol looks like a script “p”. This is the standard symbol used by aeronautical engineers. The motion of any moving object can be described by Newton’s second law of motion, force F equals mass m times acceleration a: F = m * a We can do a little algebra and solve for the acceleration of the object in terms of the net external force and the mass of the object: a = F / m Weight and drag are forces which are vector quantities. The net external force is then equal to the difference of the weight and the drag forces: F = W – D The acceleration of the object then becomes: a = (W – D) / m The drag force depends on the square of the velocity. So as the body accelerates its velocity and the drag increase. It quickly reaches a point where the drag is exactly equal to the weight. When drag is equal to weight, there is no net external force on the object, and the acceleration becomes zero. The object then falls at a constant velocity as described by Newton’s first law of motion. The constant velocity is called the terminal velocity.

Situation: Stacked coffee filters are dropped from a given height. Given their light weight they reach almost immediately terminal velocity.

Question: How does terminal velocity of stacked coffee filters depend on their mass?

Task: Prepare a video presentation for this activity. You may use the lab template but do not be limited by it. You can modify it or use your own. Be creative. The only formal request is that all the part of a lab report must be present in your video presentation.

• Use the information from the summative activity content about air resistance, and/or your own research to prepare an introduction supporting your hypothesis.
• Prepare and present a procedure with actual diagrams or videos on how the videos were prepared, and how you collected the data
• Analyze the data using graphs and tables. Use the graphs, tables, diagrams, and videos to present your findings
  • Make sure that errors are properly analyzed and presented
• Prepare your conclusions and present them with proper evidence in form of videos, graphs, tables, etc
• Make sure that the video is very close to 5 minutes (plus or minus two minutes)
• Submit the video on or before the due date.
• Make sure to peer review one automatically assigned peer

Data:

Air density near Earth’s surface: 1.225 kg/m³

Filter’s mass:

Filter’s diameter:

Known measured drag coefficients:

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