Q&A for How to Measure Viscosity

The unit of measurement used in this equation is a pascal second (Pa s).

At 25 degrees Celsius, the viscosity of water is 8.90×10−4 Pa s.

Viscosity and density relate to two different properties of a liquid. The former has to do with shear effects between molecules, and the latter with molecular mass and how closely those molecules are packed.

It would probably be difficult unless the sphere has a bright color and can be seen through the liquid. Since the result most likely won't be as exact, it would be a good idea to choose a different method to measure the viscosity.

The reference is given in the step number 4, the explanation will be as follow, when you have friction or drag produced by the travel medium (liquid in this case), the object drag is produced in the area thad directly touches the medium while in travel, since this experiment is based on a sphere, and without considering rotation or wall distances, the theoretical friction is produced in the leading half on the direction of the motion, once you pass that point and the ball is covered with liquid, the friction becomes constant (since the acceleration is given by gravity), and at that point you have achieved max speed. That is the reasoning to suggest a 2.5 cm mark below the liquid level.

It means the unit of measurement is centipose. 1 Pa s = 1000 cP roughly. Both units are correct. The formula you use will determine the units, but you can easily convert them either way.

That's the radius of the sphere. It tells you how to measure that in step 2 above.

They should be. Hence the above formula, which uses g/mL instead of kg/cubicmeter, is not intuitive. However, the final answer appears to be close to the expected value.