DISCOVER

Experiment Analysis

Observations

Observe the fall of a steel bob falling vertically in air in real time.

Write down your observations of how the velocity and acceleration of the bob in the film vary with time and distance from where it was dropped initially. Don't be overly concerned if you find the task difficult; in fact, one of our purposes here is to show how important mathematical modeling and analysis are in interpreting and understanding observations and in using that information for prediction.

Experimental Data

The location of the bob every sixtieth of a second during its fall has been converted into a table of data (Table 1) showing the time variation of the velocity and acceleration of the bob.
To supplement these data we need some additional information.

Mass of the bob
= 0.1427 kg

Drag coefficient
= 6.07 x 10-4 Ns2/m2

Diameter
= 0.0317 m

Characteristic area
= 7.892x10-5 m 2
Air density
=1.205 kg/m3

Air viscosity
= 1.81 x 10-5 Ns/m2

The drag coefficient was obtained from measurements in a wind tunnel.

Go on to the applications section to perform an analysis of this data.

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