Question

[Note: this is an open-ended problem. Various answers are possible, but some answers are better than others. The intent of such problems is to force us to use our knowledge of fluids while keeping in mind practical constraints such as time, money, and measurement capabilities.] (5 points) The objective of this problem is to devise an inexpensive but effective manner for measuring liquid viscosity at room temperature. We can use the concept of terminal velocity to help us measure viscosity because terminal velocity occurs when the viscous force (a more general term for drag force) balances the gravitational force on a settling particle. It can be shown that, for settling spheres, the terminal velocity is as follows 18u Where vs is the steady settling velocity of the sphere (terminal velocity), g is gravitational constant, d is the sphere diameter, Ps and Pa are the densities of the solid and liquid, respectively, and μ is the dynamic (or absolute) viscosity Challenge: Given a budget of $1000, design a system for measuring the viscosity of an unlabeled can of motor oil at temperatures ranging from 20 to 100 °C. Your design document should be 1-page in length and include: (1) a list of equipment with prices and a drawing of your experimental system, (2) an explanation of how to make the measurements including how you verify that they are accurate, (3) an engineering sketch of the system (apparatus, dimensions labeled, but not-to-scale is fine), (4) what you expect your data to look like, and (5) an appraisal of where you think the largest sources of error will be in your system. Make sure your design makes use of the equation shown (Stokes' Law)

Answer 1