Question

Which fluid at room temperature requires a larger pump to move at a specified velocity in a given tube: water or engine oil? Why?

Short answer

Answer: At room temperature, engine oil requires a larger pump to move through a tube at a specified velocity compared to water. This is because engine oil has a higher viscosity than water, making it more resistant to flow.

Step-by-step solution

Understanding Fluid Viscosity

Fluid viscosity is a measure of a fluid's resistance to deformation when being sheared or when experiencing tensile stress. It is often considered a fluid's thickness or stickiness. Fluids with higher viscosity, like engine oil, are generally more resistant to flow than less viscous fluids, like water, and will require more energy or a larger pump to make them move through a pipe or tube at the same speed as a less viscous fluid.

Compare Viscosity of Water and Engine Oil at Room Temperature

At room temperature, water has a lower viscosity compared to engine oil. To find the viscosity values for both fluids, you can look up their respective viscosities in a reference source like a fluid mechanics textbook or online materials. The typical viscosity of water at room temperature (20°C) is around 1 cP (1 centipoise), whereas the typical viscosity of engine oil at the same temperature can range from 100 to 200 cP, depending on the specific type and grade of oil.

Determine Which Fluid Requires a Larger Pump

Since engine oil has a higher viscosity than water at room temperature, it is more resistant to flow and will require more energy to pump through a tube at the same specified velocity as water.

Conclusion

Based on the comparison of viscosity values for water and engine oil at room temperature, we can conclude that engine oil requires a larger pump to move through a tube at a specified velocity than water. This is due to the higher viscosity of engine oil, which makes it more resistant to flow compared to water.