In-Class Activity of Fluid Viscosity Teaching Activity
1. Each team member must make a table for data in their lab notebook.
First column: Trial number.
Second column: Radius of the ball bearing.
Third column: Distance between the marks on the graduated cylinder.
Fourth column: Time the ball takes to sink between the markings on the
graduated cylinder.
Later columns: Calculations (done at home).
2. Use a permanent marker to mark start and finish lines for the sinking ball.
The “start” line should be several centimeters beneath the fluid’s surface,
and the “end” line should be several centimeters above the bottom. Make
the marks an easy integral number of centimeters apart.
3. Drop a ball into the first fluid and time its sinking over a measured
distance. Record this number in your table.
4. Repeat with other balls, until you have more than three observations.
5. Repeat with other fluid.
Note:
The density of the steel ball bearing is 7,800 kg/m3.
The density of honey is ~1,400 kg/m3.
The density of light corn syrup is 1,330 kg/m3.
The density of Dawn dish soap is 1,060 kg/m3 (another source: 932 kg/m3)
The density of Arm & Hammer liquid laundry detergent is 1,040 kg/m3.
The density of water is 1,000 kg/m3.
The density of vegetable oil is ~925 kg/m3.
Lindy Elkins-Tanton, MIT, JUNE 2010
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